Ok, well as a lifelong mechanic/technician I have used many things to clean parts and surfaces to get them properly back on line for the long run which is key. When we have something repaired we expect it to be done properly and a big part of that is cleanup and prep.

I will will use a less nasty cleaner if I think it will work, but have no sense of humor when it does not.

The op stated he tried some pretty serious methods to no avail.

Time to get nasty.