Recently I purchased a 1993 Breakenridge 37' trailer (1st timer) and have a few questions. First and most annoying is the foul odor from the toilet. I'll use the trailer on the weekends and have the holding tanks pumped on Tuesdays but by the time I get there the following Saturday the place smells very bad. I do place a deoderizor and about a gallon of water when I arrive and as the day goes on the ordor subsides but I can't live with this. Are there any suggestions of how to correct this situation so it does not smell at all?