I asked at the Keystone Service Center and again on the Montana tour whether the washer drains into the black tank. They both told me they did that for awhile but quit doing that in mid-2006 because of the number of complaints.
As others said, it would help keep the tank and sensors clean and the black tank is the one most needing cleaning. We have taken to using checmicals only in very hot weather when it tends to get a bit smelly.
See another Montana or Mountaineer on the road? Flash lights twice, it might be one of us!
Steve Reigle (pronounced Regal)
Fulltiming since 3/21/03
'03 3295RK
'05 Ford F250 SD Lariat CC SB 6.0L PSD/TS FX4 4x4
Our RV Travels (now Firefox-compatible)