Yep, pcv & a check valve is defintely the wave. I have noticed that one can pulls more fluid than the other. Twice as much easily. I'm running two small ebay cans. I filled them with stainless steel brillo type & a screen just like yours has up top there. My cans do not come with the bronze filter. That is defintely too small to get this gunk thru.

My intake remains clean as well as long as you empty your cans. I'll have to upload some pics. Literally just said this in another thread.