Adjusting valves with cold engine

Doesn't have to be any oil mess. With a hot engine.. roll 'er into the bay, raise the hood, loosen the distributer and dial the timing by hand slowly until you find a spot where the end of the radio antenna stands perfectly still ( If plugs wires, etc.. are all up to snuff, the sweet spot should be there ). Next go to the curb idle screw and lower the rpm slowly. You'll probably be quite surprised at just how slow it will idle. Now grab the air ratchet and zip the valve cover off and have very little oil loss.
Surgeons reach into living bodies every day. The prep work was done though.
How often do we get a chance to get under the skin of a running engine ?