Though it looks nice, and I've done my fair share of paint-sealing interior metal parts (on video games), touching the transformer, beyond a simple wipe down, is a bit more than I think is necessary; IMHO.
I would keep any paint remover/stripper products far far away from a transformer. As mentioned above, the transformer is dipped in varnish to seal the metal layers. It doesn't take much to cause a transformer to start vibrating with the layers just far enough separated by air to make significant noise. Also, the windings themselves are varnish coated copper. Lose that varnish and suddenly you will have cross-shorts that will change your voltage (leading to damage in electronics) or dead shorts blowing fuses and requiring a new transformer. I know I certainly don't want to pay the cost, let alone shipping costs, to get a new transformer because I wanted it to be sparkly clean.