I don't own one. The local Yamaha/Kawasaki dealer has one, the parts mgr let me use it on a pair of CV carbs that had been stored for 4 years with gas still in them. I put the carbs back together, didn't have to replace anything at all, and the bike started and ran perfectly, and still does.
Made me a believer. I don't know what the solution was, probably just mild parts cleaner.