Funny ... I actually tried ordering filters and oil by the case at Piston Ring the last time I was in there. They wouldn't give me a price break so I only bought what I needed. I need to find a deal on both filters and oil.
Oil threads. Snake oil is the way to go. I have read and tried a lot through the years going all the way back to the 2 stroke days. I use Motul 300 v synthetic. and OEM filters.