Dilution...plain and simple water is key don't fall for marketing gimmicks there product isn't what is making you pass it's the water I drink 6 bottles of water and 2 monster energy drinks(to add color to my urine to not draw suspicion) if you hand your tester a cup full of clear urine it draws some red flags. No matter how faint that 2nd line is if it's there it means you passed. Don't let people scare you or listen to what someone's "friend" did I've been doing this for years it works for me granted it's not a 100% for everyone considering everyone is different you can a few of your own things to the mix just be careful because to much water can be dangerous