What system does everyone use for air filter maintenance? Specifically, I'm looking for the filter brand, type of oil you use, and how you clean it. Now that I live in an apartment, I need to find an efficient/clean way to deal with this hassle. Previously I've used gas to wash them, then a soap and water mixture, then oil them. I don't have a place to do that now. Anyone use No-Toil in their house (sink or washing machine I've heard...)?