Thanks Kris,
This is what I was looking for.

Addition of lime is probably your best option, see:
forum.susana.org/277-fsm-planning-tools-...t-in-the-philippines

This is to seek past experience and views on how faecal sludge from emergency latrine pits about three months in use could be stabilized for effective de-watering in un-planted sand drying beds in a place with hottest month average temperature of 28.5 °C (May) and coldest month average temperature 20.5 °C (Jan). Now we are thinking of keeping the sludge emptied from the latrine pits in tight plastic tanks with vent pipe before applying in the sand drying beds. We would appreciate hearing if you have any experience or views on how long we may need to place the sludge in the tanks before applying in the sand drying beds. Please do share if you may have any other experience and suggestions. Thank you.