I pulled the subsitiution off with a 2 ounce shampoo bottle in 2 pairs of tighty whities. The urnine sample I used was given 5 minutes before entering Labcor. I was extremely nervous the sample bottle shifted and I almost lost it the lobby of Labcor. It made for one uncomfortable walk to the exam room. I also had to wait almost 45 minutes. I had the sample squeezed between my thighs to keep the temp in range. I kept the nurse talking to try keep her from noting the test strip. She didnt even seem to check. I was so nervous I didnt check the temp range on the test strip prior to handing the sample over. I was required to check my pockets, and remove my hat, but the nurse seemed indifferent and gave me the impression that rules and procedure were fairly loose when the test was for preemployment. This was also a busy labcor facility with many DOT tests for accidents etc. If I could offer any advise I would say a better method of securing the sample is needed. Perhaps a pocket in your underware. I even saw an add on tv for Ipod underwear with a pouch sown into the underwear.