I made my breather from an unused aluminum water bottle my son received from a school tour. I was able to find a black plastic hose fitting that screwed into the top, drilled an upper outlet hole, with an AN hose fitting and drilled a drain hole in the bottom with an AN capped fitting. All three fittings were sealed with Permatex RTV Grey. I put 2 stainless steel scouring pads inside the bottle to reduce sloshing. The outlet hose exits below the cowl. I attempt aerobatics (I don't perform them) quite a bit and do not have oil on the bottom of the fuselage. I attached it to the motor mount in a bicycle water bottle holder.
I drain about 2 ounces of oil at each oil change.
Since I had the bottle and took the holder off an unused bike the whole unit was pretty cheap. Probably $12 to $15 invested.
I attached an image of another unit I copied from, I don't have a picture of my setup. The difference is that my outlet is near the top of the bottle, I don't have any hoses inside. On this setup his inlet hose goes to the bottom of the bottle inside and his outlet hose on the bottom goes inside almost to the top.
Ken W
Sonex 959
CAMit 3300