[travelin texans]

If you have 1 connection to flush 2 tanks it would definitely be a 1st for me!
How could you regulate the amount into each tank, can't trust the sensors?
Why would it be necessary to flush a grey tank, which grey tank, never have in 40+ years of rving?
If it's printed "black/gray flush" that "/" probably means "or" not "and".
If putting $$ on it, my bet is 1 connection going into the black tank only!!