Yeah... I used Extreme Green. It works... very well. Took everything off my block, my pistons were spotless. But yes it leaves a grey color film on everything. Almost a gunmetal color it was kinda cool. But it came off with some towels soaked in the cleaner... some needed a brush to get it off.DrivinVtec said:if u have any polished aluminum under the hood, becarefull. them degressers lever residue on them an u cant get that shit off. Just to let u know.