lol you forgot to tell them that the fake pee has to be fresh and a certain temperature at the time of the test, or else you're completely screwed...Only real piss will be the right temperature when you figure in the time it's going to take you to get to the place, then usually there is a wait in the waiting room, by that time, your friends piss is no longer the temp it needs to be.

Dilution is the best method in my opinion, as long as you do it correctly. Read the sticky thread in regards to dilution and follow what it says on the very first post and you will be fine, has worked for me everytime.