I think the idea that Vinegar can kill weed comes from gardening. It is common truth in organic gardening that vinegar is a natural weed killer.
But unfortunately it doesn't work for weed in your blood system. Reason? being that the active weed ingredient in your system, THC, is stored in places the vinegar may not readily reach.
THC is stored in fatty tissues and can only be released when the fats burn out.
It may have only worked on drug tests that were not thorough enough, as the excess vinegar may have masked the THC. Overwhelm trick!
