Quoted from DCfoodfreak:I use the cans of compressed air for key boards. Turn it upside down and spray the free on in to the insert. The straw gives you good reach to get in there and it blasts all the dirt right out. Saw a you tube video of it
Don't you want to collect all that crud the best you can(on a q-tip) and get it out of there instead of blasting it everywhere. Plus freezing inserts is not a good thing. I watched that same video and can't agree with her methods.