Can you clean the oil filter or must the.

All oil filters are replaced, never cleaned. If any metal particles show up the goal is for them to embed in the filter material and stay there. You won't see them or know they're there, but cleaning could shove them deeper to the point where they could be forced out later into the "cleaned" side and go to an engine bearing. Any type of scrubbing will also tear up the filter material causing it to lose its effectiveness.