If I am not wrong , liquid metal polish is a solution with borax particles. Its safe for you and I think principle is to remove thin layer of bakelite.
Bakelite is very expensive today if you want to buy for example antique art deco radio or eyeglasses frame. If it looks like flamed , it indicates cotton inside. Highly flammable also. But metal polish can cause to lost its luster and may be best way is to use a 1000 -1200 grade polishing paper , it even shines your fingernails.

I will search web for you and return to you. By the way , bakelite and for cheaper smoking pipes , acrylic is the main material for smoking pipes stems. If I am not wrong , there are 3 manufacturers sell that stuff in the world. I will ask them. Buy the way , you can ask to British Museum Antiques Restoration Department. They answer to each mail in week time.
Dont rush , wait their reply.

Umut