leak
I too have used the dye with the UV light to find a leak. Typically, I find loose clamps on the oil return lines, loose cylinder head rocker cover gasket screws, and in short, anything that is not metal tends to contract and shrink a little here and there after a year of flying. I also replace all my customers cork gaskets with rubber ones, you try peeling off the old cork gaskets after they are oil soaked and cooked on and you will see what I mean. I wash down the engine with mineral spirits (I make sure not to get ANY in or near the vac pump)first with a pressure sprayer, put the dye in, run it for a short period of time and look at everything with the UV flashlight (at night). I've never used Talcum power as I've not analyzed it for corrosive ability, however I'm sure it works like a charm....
Best
Brian Wallis