Yes, indeed fellas - I've been recirculating my waste oil like this for YEARS without any problems. As I said earlier in this post, I introduced the crankcase discharge on this engine into the intake of the carb to avoid any hydrolock issues, although it would probably run fine ported directly into the manifold.
With that said, I got to the bottom of this problem I've had basically from the beginning although it was most alleviated by the Rimfire plugs. Apparently they would tolerate fouling better than these RC excels I put in there because that is the problem: the left cylinder fouls and once fouled won't clear itself. Now, the reason it fouls and not the right one is because it is getting more of the waste oil (and undoubtedly fuel mixture) from the intake manifold. I just found (sort of again) that a narrower gap is more resistant to fouling so I cleaned the plug throughly, tighten up the gap some and it fired right up and ran great.
My induction system is obviously unbalanced (which is hard to ovoid in these types of single carb installations) so I need to figure out some way to balance it - at least better than it is. In the mean time I'm going to order some iridium plugs from Adrian (when he gets back) and also carry a spark plug wrench in my kit so I can clear the plug at the field if it fouls out. I'm hoping the iridiums will be more resistant to fouling. The Rimfires only did it once in all the flights I had - but I don't really want to buy new ones: they're $32 bucks a pop!!