No such thing as a silly question, Alex. Everyone on this forum was in your position at some time.
You can use micromesh on timber ( dry ) if you want to sand finer than 600 grit, but would be more used on timber which has had a CA finish.
If used on acrylic can be used wet. Put a towel or something to keep the lathe bed dry.
As I don't turn acrylic then you may get a more precise answer from those who do.