Airportwo
We've had it cleaned and paid for it so that means it was "professionally cleaned" but whether it was a good job or not I don't know.
I learnt that if I just blow back up the drain pipe it clears and stays clear for quite a while.
Yesterday I blew up the pipe and there was quite a bit of resistance there which cleared, waited a while and then decided to give it another blow and just then the shit drained out all over me and some in my gob, tasted horrible.
Anyway I think is just the stuff in the air, maybe even some gecko crap but I don't think they get in there but it wouldn't surprise me as they are everywhere the little pricks.

Thai Dhupp
sorry for posting of topic stuff on your thread.