Lavac Marine heads - Ammonia-like pong

[geem]

White vinegar is a mild acid and is used as a domestic cleaner to get rid of mould and bacteria. (Its stocked in the cleaning section at our local supermarket). The pump valves etc should be OK for a short exposure. I suggest pump the bowl empty, add a litre bottle of white vinegar and one or two litres fresh water. Pump with lid open until bowl is empty. Leave for an hour or so as the solution will be in the pump housing and pipe above it to the bend, then flush through with the lid closed.
If concerned about using vinegar try a strong solution of (hot) fresh water and washing up liquid first, as described above but leave for longer - overnight if possible, as the detergent should not have any effect on the pump components. If the smell remains with normal use afterwards try the vinegar solution.

Regarding counting strokes of the pump, there and back is one stroke as the first movement fills the pump chamber and the second empties it.

We use white vinegar. Often we have left vinegar in the pump/pipe overnight. No issues with pump components.
Hydrochloric acid is useful to clean stubborn stains in the toilet bowl and will clean out the pipes pretty efficiently, but we only leave it in the system for a few minutes

 

[Prologica1]

Thanks SRM, another helpful idea and good to know I've been counting my strokes correctly.