I will have to try the mineral oil thing... that sounds pretty good.
We park our trailer in North Texas, (103°F yesterday), and yeah, the odors can be a big issue. We added a venturi wind vane to the sewer vent on top of the TT. The slighest breeze pulls out the odors and it works very well.
Nights camped in 2010 = 21 nights
2008 Chevy CCab 5.3L 4WD Z71
2008 FR Surveyor 291
Slpybear, Mrs Slpybear, Three Cubs