Brooks I've read about using about 3 gallons of RV antifreeze, one guy said try to get it warm before you dump it in. Recall saying dump 1/2 gallon down the kitchen, bathroom and shower, follow by 1/2 gallon of boiling water down each of the drain followed by another 1/2 gallon of antifreeze. Other say use a couple boxes of table salt and hot water.
Are your tanks enclosed at all or totally exposed? Are you running the propane heat? Might keep the fan on and the cabinets open to air circulates.