Having lived in a college town In Colorado, apparently people use it to cover up terrible body odor. It doesnt work.
https://en.m.wikipedia.org/wiki/Patchouli "In 1985*Mattel*used patchouli oil in the plastic used to produce the*action figureStinkor*in the*Masters of the Universe*line of toys." It works as a termite repellent too!
It has helped relieve stress. But I have found personally Bergamont, clove and frankincense, and ylang ylang to be more useful.
Probably, but if you are going to spend money on capsules, you should just get l-theanne extract. That is the compound in tea that gets you "tea drunk."