cyccommute 

No, acetone isn't "nasty stuff". It won't harm most modern paints nor powder coats. If your bike has been rattle can painted, it probably won't stand up to acetone as well but you can always by more rattle can paint.

Acetone is a really crappy solvent for grease and oil, however. It's too polar and doesn't really remove the oil that well. It's also not that cheap.

On the other hand, WD40 is a pretty crappy solvent as well. It dissolves the grease and oil okay but it's 25% mineral oil which just sits there serving as a dirt trap.

Stove fuel (aka white gas) is actually a good solvent if you happen to be carrying it. It's similar to mineral spirits, cuts grease and oil well and evaporates cleanly. Please don't use gasoline. While white gas and mineral spirits have flash points that are in the "safe" range (~70°F), gasoline has a flash point that is -40°F. It can be ignited at just about any temperature you'll encounter while on tour. It also contains a fair about of benzene which is carcinogenic. Not a good solvent to mess with.

Alternatively, you can skip all the mess and use a dry lubricant. Although I'm not in the habit of taking pictures of my drivetrain, this is what my drivetrain looked like after 500 miles including about 200 miles of dirt roads in Ontario



And this is what my drivetrain looked like after 1200 miles including the dirt roads of Ontario, part of the Erie Canal and a whole lot of riding on the Delaware and Hudson canal tow path.



The entire bike was not cleaned on a 5 week trip other than one quick spray in a car wash in Bensalem, PA. And the chain which I installed at the beginning of the trip lasted 3500 miles with one cleaning...when I installed it. That's fairly typical for all my chains. In fact, here's what the chain left on my fingers near the end of it's service life (I swapped the chain onto my commuter bike when I got home).



You really don't need to have a filthy chain for it to last a long time and work well.