Have you tried stone softeners prior to your flush? (Apple juice, chanca piedra, etc.?)
Also enemas and colonics are a must if you're "slow" in that department. And castor oil packs over colon & liver area really help.
I don't use ES. I can't even imagine drinking it. I do use Magnesium Citrate, but this doesn't work on me as it would on a "regular" person.(I have a concrete colon.) It works just "OK" & then I use enemas/colonics to complete the job.
The apple juice/chanca piedra really broke up my stones. Might be something to try.