I built a wand to clean the black water tank. Walmart sells them. I used a 30 inch piece of 1/2 inch copper pipe. Ball valve on one end and hose fitting. The other end I installed a copper cap. I then drilled two 1/4 inch dia. holes about 1/2 inch apart in the side of the cap so the water comes out sideways. Cleans the black tank better than the Walmart wand because it has more pressure.
2012 Jay Flight 19RD TT
W/thermal package: R19 walls, R22 roof, R24 floor
2008 F-250 Ford FX4 6.8L V10/4.10 rear axle
Curt class V hitch
Reese trunion WD with dual cam
AC6CV/7 ex-W8RUR since 1954