reusing caps kinda sucks. i try to finish all my paint wherever im painting, if im doing a piece. that way when i leave im not bringing any evidence back with me. used paint caps and half empty cans are the worst thing to have on you while your running. so i ditch both of them. but if im out bombing and didnt use much paint. i take the cap back home and soak it in lacquer thinner or paint thinner. carb cleaner works too, but its just horrible on your skin, itll mess you up big time. its not the same thing as paint thinner, what they do is relatively the same , but carb cleaner has tons of more horrible shit, same with brake cleaner. but theyll work if your in a good ventilated area. i dont bother with saving hood caps though, ive cleaned acouple out really good, only to have them piss paint all over me when i put them on a can