Way back in the days of slot cars, we used to buy bottles of some magic elixer into which we would immerse a new motor, and then run it at low speed for a while. The brushes wore in, not out, and the fluid carried the worn material away. The result was way improved brush/commutator fit and a motor that was squeekey clean inside.
Anyone know what the stuff was, and where to get it?
I have a couple of applications where a brushed motor will be just fine, and I want them to last!