Acetone is one of the "safest" solvents, and is also one of the most effective at cleaning. I don't think I'd buy into the fact there is no benefit, but maybe you didn't notice any. Did you test the SMOG numbers before and after using it? I'm not trying to make an argument for acetone persay, but isn't nearly every additive just a solvent or mix of solvents and a little oil? Acetone would be half of what's necessary for your traditional additive, just find a lube to go along with it. I use acetone a lot for cleaning and I have yet to find another solvent that cleans better. I think the bigger question is there any possible harm from using acetone, and I have no information either way on that.