I don't use brakes with Potentiometers yet but, I definitely would not do anything without first reading the proper information first. There's no telling what some chemicals may do to something like that so, I'd make sure to read up first.. I know from hearing others over the years that they're constantly cleaning them things but, I'd make sure first. There's got to be more information, you must not be looking in the right places mate.
On another note, does anybody want to run some practice races for tomorrow night's races - tonight for this?