2006 Grizzly 660 air filter

Hey everyone! Just to be up front, I’m not a mechanic… so be gentle!

My wife and I live in Haiti, more specifically the island of La Gonave. There’s only one small paved road, with the rest being like a gravel/dust/dirt trail. With that, we purchased her a used 2006 Grizzly 660 for her main "car".

The air filter is a foam filter around a metal screen, and I’m wanting to know how to properly clean it. There is no mail and no addresses here, so ordering anything and getting it shipped in won’t be possible. I’ve been Googling a lot to try and figure out how to properly clean it.

1) most people say don’t use gas
2) most people agree that you need an air filter oil to apply after you wash
3) some say to soak the filter in warm soap water to get the crud out, then apply the oil

I need to know what is the best method for cleaning and maintaining the filter. Answers like "run down to Wal-Mart" won’t help. I’ve been looking, but there is no air filter oil on the island, I can’t get any shipped in (and through customs), and it’s at least a day long trip to make it into the biggest city that may or may not have it: Port au Prince. There’s a few types of engine oil that local places have, but that’s about it. Will engine oil work if I can’t get filter oil?

Thanks for any help you can offer me!