Or......you can just buy some air filter oil. It's got some tacky stuff in it and it does a 100% better job than just oil. Any m/c shop will stock it. I'm sure that you can find some on E-Bay as well.
It could be, but I'm not sure. I have some Bel-Ray stuff and another brand that escapes me at the moment. I've got some in both a spray can and a bottle. I haven't had to buy any for a long time.