Just last week I sat down on a wet seat. You could not see it. Apparently they have chosen a great pattern for cushions - if you can't see wet what else are we missing????
The FA said oh yes - someone spilled water on the last flight.
If the FA's can't remember something like that how does anyone expect a cleaning crew to see it. They can't touch every cushion and check for wetness.
They changed the cushion before takeoff but I too sat in wet pants
I touch the seats before sitting now. Unless I get the leather in first