For the Wee the PD Oiler was the best thing since sliced bread. I seldom cleaned the chain though, maybe once or twice in it's entire life. Would get 15k+ out of a chain without much problems. It helps if you buy good quality chains too, I usually bought DID.
On the Tracer I'm experimenting, I'm only using WD40 to clean the chain and when it's clean I apply WD40 as a coating. I might give it a quick spray of WD40 in between cleans, but no real lubrication at all. I don't ride anywhere near as much as I used to with the Wee so the cleaning intervals aren't crazy. At a guess I'd say it's cleaned every 600 miles. The chain stays clean, doesn't rust, I don't have oil going everywhere or dirt getting stuck in the chain oil and making a grinding paste of it. I also can't see any significant accelerated wear on the sprockets, but I doubt I'd be able to tell that after 2000 miles anyway.