I am afraid you are using the ...

I am afraid you are using the wrong biological tool for the job. As you have discovered bacteria trying to do the job of another microbial group comes with its own set of problems. The sludge and grease traps use a 3rd group of microbes. They are called Archaea. Their  5 billion year natural function is to breakdown ALL organic matter to its elemental state. (the original recycler). When finished nothing left to dispose.  It was available in South Africa. If not now you can always start your own business selling and cleaning grease traps across the Continent.  Details upon request.