Hmm, I feel like a full-body suit would be required for something like that, with some sort of neurostimulator-type technology in it. Little nodes of some sort, positioned over strategic parts of the body, that would simulate the sensation of being tickled in various ways, with the VR headset providing the environment and scenario for you. Or perhaps the nodes by themselves, so that you can position them wherever you want them, or individual portions of the suit, so that you could choose to buy only the parts of you you intend to have tickled--a shirt for the upper body fans, or a pair of socks for those of us who would prefer to have our feet titillated. Alas, such technology is probably fated to remain in the unreachable realms of science fiction, alongside teleporters and starships...