I have a 4510 Amsoil universal filter in a cold air induction box I built and I have a question on cleaning. Has anyone ever tried wet cleaning one of these nanofiber filters? I know they are made to clean with low pressure compressed air but mine got damp in spots it looks like and has made little spots where the dirt seems to have stuck. I think the moisture came from blowing snow that came in through the cowl and into my intake that's in there. I know I saw a little bit of powder snow dust in the filter box once during the winter. I'm just assuming this is why I have little dark spots here and there. I just wondered what you all thought. I went ahead and ordered another one to have on hand in case I mess this one up but I think I might try cleaning it gently with K&N filter cleaner and water and see what it looks like. I guess I could talk to Donaldson too and see what they have to say. -Mark