I am running the Losi filter system on my D8 and D8T, along with the RCPro foams that Rex linked to. Yes, I am sponsored by RCPro...honestly though, the foams are DIALED. I do oil both as I run in dusty conditions. I also do not reuse filters. Get dirty once, toss em. As for my procedure, I soak em in oil, then squeeze the excess out by rolling them in a paper towel.