I've removed lacquer from horns when they looked ugly. Fun story: when our symphony section was being courted by one trumpet manufacturer we each ordered a Bb and C in raw brass (because that was in vogue at the time) but the valve caps were lacquered. I got some Zip Strip put it in a jar, and dropped the valve caps in and let them sit for 48 hours. The jar was on the kitchen counter. A friend came by, saw the jar with this white, gelatinous liquid inside, and since it was in the kitchen assumed it was food. He asked "What's this?" as he picked it up and inhaled from the jar. He staggered back with wide, bulging eyes. (When smelling something new, follow the instructions from chemistry class--wave your hand over the opening and smell it indirectly.) We had some fun with an "ugliest horn" contest, by seeing who could go the longest without polishing their horn. Raw brass will turn some interesting colors if you wait long enough. Have fun!