I have read about acetone nail polish and a q-tip for before baking clay, so I tried afterwards as well, but my piece became smudged with white. I must have used too much. Thanks for the tip about changing q-tips however, Kristen!
Otherwise, I have also heard a fine sandpaper is what should be used if choosing to go that route...
It seems like cleaning before is the best option, according to you guys so I will work harder on that and try out your wet q-tip suggestion as well as other things I've learned from other threads.
Thanks again!