Been some good advice here.
I use to test myself regularly to see how my body reacts to thc levels. That why I know I can usually get clean in 3 weeks after heavysmoking for a few months.I use to find that I could smoke 3 days in a row and on the third day I could be clean. And I never did anything special except drink green tea and cranberry juice mixed with vodka. But I got to tell you its a big pain in the ass to have to put your toking on a schedule.:jointsmile:
Thats why I finally got smart and started subbing with synthetic urine. You don't have to have access to a microwave. Pickup some of the cheap hand warmers and have them available. You can stcik them in your pocket. They can not make you piss on command.It takes time. Thats all the time you need to warm up the synthetic urine.
If you want to go the natural way, metamucil will definitely help by keeping the colon moving. The only way to know for sure is to test yourself. Pickup some cheap thc strips on ebay. Then if nothing else in case of an emergency you'll know if you're going to piss clean.