First Acetone Use

For starters, it should be pointed out "fingernail polish remover" and "100% acetone" are not necessarily the same thing, as fingernail polish remover is often diluted with water and/or has fragrances added to help mask the strong acetone smell.

Secondly, yes, it does make a great deal of difference what the "stuff" is. Acetone is a chemical, not magical; it will only dissolve or depolymerize certain things, in obedience witht he laws of nature. If the "junk" is actually corrosion, acetone won't do anything at all to it, for example. Using acetone on a random coin will rarely do harm, but will rarely actually do anything visible at all.

I recall trying to clean a pile of Thailand coins with acetone that had been glued to a piece of cardboard for decades (as is commonly encountered in "tourist sets" from that region). The tin and silver coins cleaned up great, the bronze ones only with difficulty and the cupronickel ones remained stained by the acidic vapours of the glue.

Since you say the acetone didn't remove much, then posting an "after" pic is going to be almost as good as posting a "before" pic. So post away.

What Sap said is about it. And as to those coins you just posted, I'm not sure anything would help those. They appear more damaged than coated or plated or anything.
And if your going to use Acetone, remember it is a lot cheaper to get the pure stuff in a can from almost any place that sells paint and usually a lot cheaper than finger nail polish remover.

That coin is covered with corrosion. Acetone won't touch it.

It is usually easy to tell the difference between corrosion and other stuff. just takes a little time . just remember; acetone will eliminate grease, oil, fingerprints, some dirt and contaminants.
as far as corrosion; an electric wire wheel, another words forget about it !