not sure about its laxative effect but i know victorian "ladies" used it to make tea. they claimed it improved their complexion "so their husband would favour them above any other possession". should try it with my OH, anything to make him put down the xbox controller! SO, laxative effect on you or the tort?!
alot of people say its now wrong to feed it to your torts, but i still have tons of it in my garden so as much as i try to get rid of it, there will always be some left for them to nibble on. i have never had any problems feeding a small amount of it.