The oil does more than just make the cotton sticky . The oil also attracts particles by chemical attraction, kinda like a magnet. Oiled filters work better dirty also. I just recently replaced my old K&N with a Green and the Green was actually less expensive here locally than the K&N, but not by much. Upon inspection the Green is manufactured to a much higher quality than my old K&N and seals much better in my stock airbox. There is also a claim out there that Ford will revoke your warranty on some of their diesels if you use a K&N but they are OK with the Green. This claim needs to be substantiated tho. I dont see any scientific reason why cold oil shouldnt work. If the oil freezes on the filter imagine whats happening to your engine oil before startup !!!!!