next time try light heat and candle wax. that or 1:1 ATF Acetone. Kroil is great but when it comes to stainless steel on stainless steel threads locking up, its a mechanical issue, not a corrosion issue. typically the only solution is to retap the threads and pray that the antiseize you put in there lasts, on an exhaust system its nearly impossible to win this battle. this is why i drill out the hole and install a nutclip. DONE