I can't speak to pectin or certo, but I can speak to dillution. I used to be in a job that required frequent UA's and I was always dirty with more than just the main topic of this board. I never did anything to pass other than drink ALOT of water, anywhere in the neighborhood of 1 to 2 gallons in the 4-6 hours prior to the test which would cause me to urinate roughly 10 times before testing. Fortunately it was never looked at for missing vitamins or whatever was mentioned before, but I never once tested positive. Plain and simple dillution works. The side effects are that you can't be far from a bathroom for the rest of the day, but the benefit is worth it.