I broke in an OS 91 four stroke engine the other day. I couldn't get the muffler to stop leaking. I tried to loosen and re-set the nuts on the stem to engine and muffler. But it kept letting exhaust fluid leak out. I want to try the high temp silicone I bought at the auto parts store. What should I use to get the residue off the threads? I was thinking of using Formula 44. Will that be OK? Or can I just wipe the parts off and apply the silicone?

Thanks for any help.