I boiled a couple of Mk6 altos in a big pot of water once.  That works.

There are a couple ways.  The traditional way is to rub it off, which removes some of the metal in the process, which is why relaqured saxophones are typically worth less, and sound different that original laquered sax's.  In the last few years, some people have started using a chemical method, which shouldn't remove metal.  I think Steven Howard mentions something about it on his site somewhere, but I couldn't tell you where.

We have a place here that strips antique furniture and more in a dip bath that is heated. I took a wall hanger saxophone and removed all the keys to test it out. Came out very good with the engravings still sharp and clean. Just a thought but definitely stay away for sanding or buffing. Chemical strip is very good.