Vinegar will help.
Niacin (vitamin B6 I think) will help as it will flush things out of your system, but THC and it\'s metabolites are fat soluable as you know and I think Niacin is more about flushing things out of the direct blood stream.
As for eating fats, I think you actually want to process the stored fat in your body, not process new fats which have no THC stored in them.
So you probably want to exercise.
That all said, it\'s rare as hell for anybody to not be able to clear a THC test in under 30 days. Even regular use. I wouldn\'t sweat it too much, but you might as well add some vinegar to your diet and exercise a bit more.
Also if you still want to get stoned you can obtain some JWH-018, JWH-081, JWH-073, JWH-211 or other synthetic cannabinoids. I haven\'t fucked with these in a while but most of them I\'ve found to resemble cannabis almost exactly, and they won\'t show up on drug tests.
I think JWH-018 and -073 and some of the others are now banned in a lot of places but a lot of them aren\'t banned and they\'re easy to find with a google search