IMO it is a waste of time to prefill an oil filter. It only takes about 2 seconds for the filter to fill and the system to pressurize after the engine is started. The engine is not going to be damaged by this, particularly in view of the fact that the engine is not under a load when it is started, and all of the bearings still have some oil in them from having been recently run (they are not dry). I don't recommend that anybody try this, but you can idle an engine without any oil in it for a substantial length of time without causing any major damage, but it will quickly seize as soon as you put a load on it.