John,
I am a ship's engineer by original profession, and used to crawl front to back through those hot oily contraptions they call engines for inspections. Nowadays, whenever I can get by without oil all over me, I will choose that option. My gas planes stay clean after the first running in period. I just love that, and it is not laziness I can assure you. The plane too is not jeopardized by oil seepage into the wood and nooks and crannies, or cover seams (I hate cover). For that reason I use an air filter on my engines whenever possible, so all blowback is eliminated.
I would however never use less oil than the percentage needed by the engine just to save me some cleaning. For that reason, my standard oil mix is 3% (1:33) for hard working glider tow engines, and 2.5% (1:40) for loafing around.