Does anyone remember a product sold as, I think, "Toy Train Clean" or similar name. It was in a translucent bottle and the cleaner itself was pink in color. It worked quite well on old Lionel and AF trains that had seen better days, although you still need to be careful about how hard you scrubbed and you have to avoid any decals. I believe it may have contained a bit of bleach.
I'm trying to find it again but the person who sold it may have gone out of business.