Having tried many of the lubes listed herein the easiest was a drop of 100LL every time the cap came off. Grease, EZlube and others washed off after 4-5 flights and back to dropping fuel. So . . .
I did a little research on the solubility of DC-4, DC-2, EZlube, Lubriplate Lithium, and many others in 100LL. All were soluble in gasoline
I finally found a pure PTFE product called Krytox GPL-205. It claimed not to be soluble in gasoline so I cleaned the caps and o-rings then applied the Krytox. Three BB sized balls and worked it around. A tiny smear on the pivot too.
8-9 flights and three fills to tip top and it the operation is still butter smooth. If this works, a small tube will last till TBO.
BTW - a 0.5 OZ tube
was over $20, so not the cheap solution but hopefully it is lasting.
I think I need better bait. It's clear many people don't read past the first sentence. With this lube, the cap does not stick and need the press after lifting the tab.
edit 8-11-22: my caps have not leaked, nor stuck even once since using Krytox.