Reply by Loren

Another option, and preferable because chipping shouldn’t be
a great problem (lacquer is brittle) is to ebonize the work and then
topcoat with shellac, which polishes beautifully, or some tougher
clear finish, but not laid on to thickly.

Shellac and wax works fine in the bathroom if the room is adequately
ventilated. Don’t be put off by fear the finish will melt immediately
on contact with water or alcohol – it is more durable than
sellers of varnishes would have you believe.