ARC went bankrupt but have started trading again (apparently), have you not tryed to find ther official site?
When i had one on my old delsol i used to just blow it out with the air line mate its only sponge so it seemed to work quite well.
Scrub filter with lynx shower gel, spray with dirt retainer!
No you can clean them no problem, bit of mild detergent.
Just be gentle with them, there's two filters right?