The oral fleet laxatives are magnesium citrate... all forms of citrate that you can get into you will help.
I wouldn't put drinking one of those at the top of my list of ways to do it though.
If you try it don't go far from a toilet.
I've had to use those prior to medical testing before and Holy OMG...
They clean you out!
Another easy access form of citrate that you can take without those effects is Potassium citrate.
You can get that at any health food store in capsules.
I also take that daily, but bear in mind that I take a medication that causes me to deplete potassium I have to take it to replace. If I don't I get hypokalemia symptoms.
I do not however think that it would be a problem to supplement some potassium citrate short term to help pass a stone(say 200-300mg 2-3 times per day)... especially if you are drinking a lot of water and urinating frequently, which you certainly should be.
Our body is our subconscious mind, and anybody who thinks that their conscious mind is running the show is seriously mistaken. In fact the conscious mind just may be the most narcissistic entity in the universe, it thinks it's running the show. It's not.
~ Nora Gegaudas
"Everything can be taken from a man but one thing... -- to choose one's attitude in any given set of circumstances, to choose one's own way." ~Vicktor Frankl
And that's why I'm here eating HFLC Primal/Paleo.