I tried to empty a blocked holding tank. Had to do it from inside the head as a 90 degree elbow prevented poking anything up from outside. Lost control!! 90 litres of gunge into gleaming white shower base and into bilge underneath. The shower base clearing was bad enough, but how the hell do I get the rest out from under the shower base moulding??There is a gap of less than an inch at the top, plenty of room for the obnoxious liquids/solids to get down but near impossible to get out. Anybody hadexperience of this, any solutions?? Alan