I asked these same questions about a year ago about SMELL and FOAMING. All I got for an answer was replies such as, "not all urine bubbles" or "the techs arent paid enough to sniff everyones urine". I have successfully subbed with quickfix at a temp agency where they used a 5 panel dip stick test similiar to the ones that you can buy at any drug store. They did not smell or look at anything except my temp and my negative result, but I have always been paranoid about those same questions if I had to take it at a doctor's office or Labcorp, etc. Anyway, if anyone has answers to the SMELL and FOAMING issues, I would like to know as well. You're already nervous enough when subbing, the last thing you want to worry about is a pissed off/by the book tech who is just looking to catch someone subbing. I understand the cat and mouse game, but the slightest thing can send off a red flag to the tech, who would then make you take another test (either supervised or unsupervised. Regardless, at that point, your dead in the water because you have already used your quickfix and if you could pass with your own urine then you wouldnt have subbed in the first place. Please help me and the OP.