myronman, I gotta take exception with the unburned powder acting as a lube, I just don't agree with that part of your statement.
As for my unofficial testing of brake and electric motor cleaner. First there is Break cleaner, Brake and electric motor cleaner, then there is electric motor cleaner. The stuff labeled a brake cleaner, I wouldn't use on a firearm, it seems to be the nastier of the three and it does leave a residue. I "tested" the ones labled for electric motors. I let the stuff stand for an hour (had to replinish the fluid to keep it wet frequently) on:
Styrofoam, teflon thread tape, electrical tape, plastic cap from a can, o-rings, rubber air line covers, painted wood, painted metal, varnished wood, oil finished wood, sandwich bags, plastic wrap and a condom. After less than thirty minutes the condom started to leak, everything else was unaffected except the adhesive on the electrical tape. So unless your taping on your condoms, this is a good economical product that I have used for several years.