I was just checking a couple things on Duncan Racing's site. I noticed they had a "how-to" for cleaning the air filter. They recommended the use of Maxima foam filter spray. I may get some and try it, as I've got two filters to clean and I won't be riding any time real soon.
As far as yucky for your fingers, spray the filter pretty good, then put it in a ziplock bag and spread it around the filter like that, and when your done spreading, just keep it in there till your ready to use it, nice and clean.
Scott