I'd like to hear some ideas, too. I've been using baking soda on the oil felt of my 301, changed it 3 times as it pulled the icky stuff out of the felt turning into a brown paste which helped but I'm thinking of trying clay kitty litter as it absorbs oil & odor. The 301 case is in a sunny store room as we're not getting a lot of hot dry weather here in MN. My new 15 has some musty/smoky smell too but not too bad unless you get your nose in it. I think it will air out. I'll be glad to hear some other ideas.