Thank you for your interest in Septic Scrub. There should be no problem with a freeze up causing a back-up. Septic Scrub chemically reacts with the sulfides and polysaccrides to make them soluble and available to aerobic bacteria. Oxygen is also released which helps restore aerobic bacterial action. This reaction is over very quickly and the result is almost immediate improved flow. 

You do not have to drain the tank and move out. You may continue to use your system. In fact we encourage you to. Septic Scrub reacts with the anaerobic crust which is generally within the first 2-6 inches of the laterals. The first addition breaks up some of this crust. This creates new flow channels for the water. Each additional treatment moves further into these new flow channels to extend the treatment. The only requirement is that the laterals be free of standing water before treatment. If there is standing water, the product cannot flow into this area outside of the laterals.

If your system has a distribution box, it is generally within 3-6 feet of the outlet of teh septic tank and in a straight line with the inlet and outlet of the tank. As you know however, your system and my system are never normal. You might try to gently probe and find the outlet pipe from the tank and try to follow it until you find a box. An iron rod is generally used for this. If the outlet pipe is PVC, you probably cannot damage it. If it is clay pipe or perhaps the aspalt pipe, you must be careful not to break the pipe. 

Please call me at (888) 352-7226 if you have further questions.