i think i used quick fix for mine or something similar. ive done it 3x with success at lab tests. all of mine came with something similar to a hand warmer and tells you that you should crack it and attach it to bottle 30 minutes or so before testing. i would just crack it, rubber band it and stick it in my shorts. always worked for me... i dont trust dilution. ive worked/managed a head shop for a few years and had alot of people who bought it and came back wanting a refund ((but than again these people are fucking stupid and probably didnt read instructions because it says if it dont work your supposed to mail back to company for refund - not the place you bought it from)). ive never used em - so im not going to try and give advice. much easier to use the synthetic and deal with heat issue than to deal with dilution IMO. good luck interview GT.