Ironically, cleaning can be a very messy process. But that does not have to be the case all the time. With formula like the Walex BOI-11530 Bio-Pak Natural Holding Tank Deodorizer, this is a thing of the past. It comes in a convenient form that provides portion control while being incredibly easy to use. So, say goodbye to that normally messy process of cleaning your RV holding tank. Simply drop a pak in, and the rest is history. The formula also happens to be environmentally friendly and starts work instantly. It is also very great when it comes to keeping bad odors at bay quite effectively.