Fil
In America, magnesium citrate (is that right guys?). in Australia, milk of magnesium (I'm going to try this next time), then there are magnesium powders and capsules I think.
My opinion having done several flushes of different styles is that if you don't take the
Epsom Salts , it is better to fast for a couple of days before the flush (if you can) and do enemas to make sure you are cleaned out. If it's a bit clogged on the day after drinking the oil, try an enema to wash it all out.
Last time, I didn't really fast and only had one tiny dose of
Epsom Salts which had no effect. The result was all my green stones embedded in solid pale clay-coloured stools. Not satisfying at all as I couldn't see what was what and it took a couple of days to get it all out!