I agree that I think steel wool would affect the performance of the engine. I'm not saying, "Don't do it", I'm just saying, "Don't do it YET"

Remember - KEEP IT SIMPLE. The less you have, the less is likely to go wrong.

So don't pre-heat, don't put anything in the muffler, don't do anything beyond a basic system at first. If it works, you obviously didn't NEED to do any of that stuff. If it DOESN'T work, THEN it's time to start experimenting.

One thing worth mentioning... Add a third line to the tank for filling and emptying. If for any reason you land with extra oil, you'll want a way to empty the tank before leaving the field.