If it's your own property just run the grey open all the time into a grassy area and never worry about emptying it.
TT: 2015 Jayco Jayflight 26BH Elite
TV: 2014 Ram 1500 Sport, 5.7 HEMI 3.21, Firestone 1000# air suspension. WD hitch w/800# bars
SOLD: 2012 Jayco J-series 1007