What Duncan Said,,,"Brake Cleaner". It's my mechanic in a Can. Cleans AFM's,,,funny enough brakes (removes spilt brake fluid as well as cleaning brake grunge. This stuff SHOULD be in everybodies toolkit.
I even use it to clean up his oil seepage between races.
If you really want to do a test,,,get a clean piece of glass and spray some carby cleaner,brake cleaner and contact cleaner on it, one at a time and you tell me the results.
Neil.