I've noticed that manufacturers are making similar recommendations to avoid alcohol. I have heard that it can degrade electrical continuity, especially on smaller scales.
A word of caution on the cleaning products sold in electronics stores-I have found that they will attack painted surfaces. One of my GP-9's had permanent "freckles" on the painted surface because I was a little too liberal with the electrical cleaner.
I like to use a little of my wife's "Goo-Gone" to break down the black residue on track and wheels. Be careful to use only small amounts and wipe it off when your surface has been cleaned.
