Yes and no. You are correct on your percentages. So less oil than normal glow operation means less oil on the plane. However, there's another factor. There is gasoline in the gas/glow mixture (obviously), and gasoline burns hotter than glow fuel. The oil in the mix burns. Therefore, there is very little, if any, glop to clean off the plane with either gasoline, or gas/glow operation provided the gas/glow mix is done properly. Some guys insist on doing the gas/glow with normal glow fuel. What you want to use is glow fuel for "Large Super Tigre" engines. It has only 10% oil to begin with, and that is what to mix with 2 parts of high test gasoline.

The advantages I have encountered with gas/glow are:

More power; usually a couple of hundred rpms
Easier starting
Smoother, lower idle
Less weight
Less worry of interference and component mounting

The only disadvantage for me, is that I have to run the engine out dry and use an after lubrication just like my normal glow engines, due to the fact that the engine is now running with alcohol and nitro in the mix, which can cause corrosion if left in the engine for any length of time.

AV8TOR