I always used just soap and water to clean my filters but i cleaned them quite often so they never got so grungy that I had to use and kinda solvent or filter cleaner that out there, that could break down the foam and cause them to come apart and suck dirt.
Id just use the run of the mil bel-ray filter oil cause its all oil no matter how you look at it or if that no-toil stuff is the about the same price you could try that or i guess I should say it may be worth trying, also if your ever in pinch and you need to clean your filter just find sink and clean it with the sop and water and when yur done get all the water out that you can and then put pre mix oil on it and keep squeezing it in till the water is displaced, then youl have dry filter and ready to ride, thats only if you didnt have filter oil on you at the time.
They say not to slap a freshly oiled filter on our YZFs Paul. Supposed to let them sit overnight because they'll suck the oil out of the filter???? And thats a bad thing. I've always let mine sit, so I'm not sure if it's true.
I use the K&N foam filter oil/cleaning kit. It's cheap and works good.