Yeah man, I used to make "spice" before the initial bans and even those chemicals were only tested for ~8-12 months before release, once the government caught on and banned shit, chemicals were being tested by being applied to plant matter, no lab time at all. That shit isn't safe one bit man.. To dissolve the chemicals most manufacturers (including myself) used acetone to break down the chemical and spray the plant matter.. I will admit, I made a killing on the stuff and it wasn't illegal so what the hell. My wife didn't want me doing it anymore though once the ban happened and we all know, what the wife says goes.
While it evaporates 100%, you don't have to spray acetone on pot. These people are probably using cheaper solvents than acetone.. did you know the molecular base of some of the chemicals is similar to that of moth balls... do you like smoking moth balls?