Steve, the Uni filter is very easy to oil and clean. You do not take it apart. You can buy the UNI oil and cleaner in a combo pack. To oil you just spray the oil evenly all over the inside and use your fingers to spread out. You really only need to lightly oil - too little is better than too much.
To clean all you do is spray the cleaner foam all over in and out and work in. Then rinse with a hose and let dry. If it still feels oily after rinsing, do it a second time. It's really very easy. I clean mine once a year.
There is no un-oiled version although some people choose to use the filter without oiling. IMO, I think lightly oiled is best.
