A little guidence please

I will try to make this post as short as I can. The company I work for just started a new drug testing policy. I feel it is either due to the Insurance company, or a customer we are trying to get who are supported by the state. I am not sure when I have to take this test, or if I even am going to be taking one. So far I have just had to sign for post employment/random drug screening and a background check. I have a friend who has supplied a sample for me to use as a sub plus I have stopped smoking until I know exactly what is going on. I have my friends sample in the freezer in a jar with a lid on it. I would like to know whats the best way to unthaw it and how long is it good for in the freezer, and how long is it good for after it has been unthawed?

My final question is how well do those drinks work that are supposed to give you like a 4hr window to drop clean in. I just got off probation so I havent smoked in like 6mo. Once I got off though things changed. I smoked for about 3 or 4 days straight then I would stop since I work 3 12hr days. I just don't smoke the days I have to work. I did this for about 2 weeks until I recieved these 2 documents. I have been clean for about 10days now. I am 5' 9" and weigh around 135lbs I have a high metabolism and very low body fat. I bought one of those drinks that are supposed to give me a window to drop clean in just in case my drop is suppervised. My question is will this drink work for me just in case I am supervised?