Can Someone Please Advise On Acetone Dip?

I buy pure acetone by the quart or gallon at a local paint store.

Soaking duration with acetone: You can't over-do it as acetone does not adversely affect the metal. The duration need is determined by what you are trying to remove. If you need a time, start with 5 minutes and check the results. I use a cotton ball after soaking and sometimes use a well soaked q-tip to get at details as needed. Be cautious with the q-tip if you go that route and use paper not plastic stem ones.
Here is a link to a discussion about a coin I soaked in acetone: http://goccf.com/t/397521

I rinse with acetone - some folks rinse with clean water.

A. In and out. Use glass, ceramic or metal containers to hold your acetone - don't use plastic. Acetone is very very good at depolymerizing and dissolving certain kinds of plastic, and it's impossible to tell if acetone will destroy your plastic object just by looking at it. Likewise, any working surface (tablecloth, benchtop, etc) should be plain wood, metal or stone; any prepared surface (eg. varnish, paint or lacquer) is likely to be damaged if acetone is spilled on it. Don't wear synthetic-fibre clothes, otherwise you might find an acetone "moth-hole" forming if you spill any acetone on your clothing; "synthetic fibre" is just fancy-speak for clothes made of plastic. Having a metal tray of some kind to lower the coin into the dip and raise it up again would be good; using gloves, or bare fingers, can add contaminants to the acetone which can end up depositing on your coin.

B. If whatever-it-is that you're trying to remove from your coins doesn't start to dissolve in acetone within a minute, soaking it for longer isn't going to help. Isn't going to hurt either, just won't help. Gentle swirling can help; personally, I use a glass eyedropper submerged in the acetone to "squirt" jets of acetone onto the more stubborn spots of goo.

C. Acetone is acetone, or at least it should be. Acetone-based domestic products like nail polish remover often have fragrances to try to mask the "chemical smell" of acetone, but you generally want to avoid mystery contaminants in your acetone if you're soaking your coins in it. Some jurisdictions require the addition of denatonium benzoate to acetone before retail sale; the teeny tiny amount of denatonium usually present isn't going to make much difference to the outcome (though it will make your coins taste terrible - which might be a good thing if your pets or children keep trying to swallow your coins).

D. Nothing. Or rather, nothing except more acetone is necessary. It's usually good practice to rinse a coin in fresh acetone, if it's been sitting in "dirty" acetone soaking for a while. Some people advocate a final rinse in deionized water; this is largely unnecessary; there won't be anything left on the coin after consecutive acetone rinses, that water might conceivably dissolve.

E. I think you're more likely to find acetone for sale in a hardware store, than a pharmacy. Pure acetone has no medicinal use, but it's often sold as a paint stripper.

Other things to be aware of:

Safety: Acetone is highly flammable, as are its vapours. Treat it like you would treat gasoline: use it in a well ventilated area, don't smoke anywhere near it, don't have any other flames or sources of ignition nearby.

Acetone is highly volatile - it evaporates easily. It's more volatile than water, alcohol, gasoline or any other solvent you're likely to encounter in everyday use. Any open dish or bowl of acetone left sitting around is going to evaporate away to dryness within a couple of hours, especially in warm weather. Always tightly seal up your bottles and jars of acetone to stop it from escaping. Store it in a cool place.

Health: Acetone is as toxic as alcohol, but without the pleasant side-effects often attributed to alcohol and it tastes terrible, so don't drink it. Most people find acetone vapours are generally unpleasant, but they are not necessarily very harmful. It probably isn't any more carcinogenic than gasoline or any other petroleum-based product. Acetone is, however, very good at dissolving fats and oils; we want this property when cleaning coins, but if you splash it on your hands, it will suck the oils and waxes right out of your fingerprints and redeposit that stuff all over your fingertips when the acetone evaporates away, making them turn white. This washes off in soap and water, but some people can be sensitive to their own body oils getting redeposited on themselves, so acetone is formally classified as an irritant.

Gloves: You can try wearing gloves, but gloves are made of rubber or plastic and, as already noted, acetone can dissolve certain kinds of rubber and plastic; unless your gloves are acrylonitrile or some other synthetic rubber designed to be resistant to acetone, you're probably better off without them. Gloves also make it generally more difficult to handle a coin, especially if its slippery and wet.

Just straight acetone. Forget the gimmicks. Squirting?

Thanks to all for your advice. And an Extra special thank you to Sap for your very detailed, elaborate and clear answers!!!! VERY Much appreciated!

"Lighter fluid" is typically comprised of a mixture of aliphatic hydrocarbons, not entirely unlike gasoline. As with gasoline, it can be reasonably effective at removing certain kinds of organic deposits from coins. It will not work "the same" as acetone, but will work similarly. There are some forms of "goo" that will readily dissolve in acetone, but not lighter fluid; there are others that happily dissolve in lighter fluid and are more reluctant to dissolve in acetone. But acetone generally "works better".

To get more technical than a non-chemist would feel comfortable doing, there is a "ladder of polarity" which every molecular chemical substance can be placed on. It ranges from "non-polar" (like hexane), through "almost non-polar" (like xylene), weakly polar (acetone), and strongly polar (water). Solvents at one extreme (like water and hexane) are terrible at removing "goo" that is made from substances from the opposite end of the polarity ladder - thus, water is terrible at removing crude oil, and hexane is terrible at removing dried fruit juice. Detergents, for example, are very good at helping to dissolve things because they are comprised of very large molecules, some parts of which are polar and some parts of which are non-polar; the non-polar bits stick in non-polar oily goo and the polar bits stick to the water the detergent is dissolved in. Acetone, being a "middle of the road" solvent, is pretty good at dissolving most things, and very good at dissolving other weakly-polar substances.

Lighter fluid, being composed of molecules more or less similar to hexane, is chemically way down at the "non-polar" end of the ladder.