I’ve put my wife through that test several times throughout our relationship. With her legs tied apart, I’ll remove the stocking from one side and ask her to decide which tickles more. Tickling both feet at the same time for a bit, then going back and forth between one and the other. She always claims that the bare foot tickles more, but her hysterical reaction seems to be the same for either. It’s difficult to know if she’s telling the truth or not, thinking that I might loose interest in the more ticklish stocking foot if she lies. Either way, her feet get a thorough workout in and out of the stockings, but since I’m still not convinced of the true winner, I’ll continue to repeat this test as often as I can.