Found Some Pure Acetone, How Do I Use It Correctly?

With acetone you will not have to rinse. Normally a quick soak will dislodge most material on a coin.
The Acetone will evaporate from the coin rather quickly

Thanks.

What's the best way to hold the coin........tweezers?

Don't use tweezers, especially if they're metal! They can damage the coin.
Artificial nail remover? That sounds the similar to nail polish remover. Double check if it's pure, sometimes marketing is sneaky and put 100% acetone on the label, even though it's not pure and they added things like fragrance.

I use my hands. Just don't keep in contact with acetone for too long because it dries skin. You can wear gloves if you want.
Just make sure whatever you use isn't of organic origin (like plastic, paint, etc. so no plastic cups!) because acetone dissolves it too. I learnt that the hard way, the plastic bottle I kept the acetone in almost dissolved, and I peeled paint off when I accidentally spilled some on it.
And also make sure the place you're working in is well ventilated and there is nothing that can start a fire (fire, sparks, those things) because acetone is flammable.

Edit: No need to rinse with water and pat dry I say, because acetone will evaporate off the coin in seconds.

Acetone does evaporate off the coin quickly. As others have said elsewhere, the best way to make sure that none of the stuff that just got washed off the coin by the acetone gets re-deposited back onto the coin when the acetone evaporates, it is best to have two or three cups or bowls of acetone, and submerge the coins into each in series: bowl 1, dry, bowl 2, dry, bowl 3, dry. Try to minimize dunking your fingers in the acetone, because it will suck the oil out of your fingertips and re-deposit that oil onto the coin or anything else if it allowed to evaporate away. Acetone does not "dissolve" plastic so much as depolymerize it, but the effect is similar. If you use gloves, use gloves made out of a material that is not affected by acetone (test the gloves first).

A water rinse is unnecessary but does no harm if it makes you feel more comfortable doing it, just remember to use distilled/deionized water rather than tap water (especially if you're in an area where the tap water is loaded with chemicals) and dry it thoroughly afterwards. If you don;t have access to DI water, I'd definitely recommend skipping the water wash because I'd trust the purity of the acetone over the purity of the water.

And, as others have said, treat acetone just as carefully as you would treat petrol/gasoline: poisonous, keep away from small children and animals; flammable, no smoking fires or sparks; highly volatile, keep well ventilated.

If I was smoking cigars around my boats and cars and bikes I wouldn't be buying raw coins and soaking them in acetone

The only thing I am missing from that equation is the boats.