I still wouldn't use it around my frogs. Just because it's natural does not make it safe...afterall arsenic and cyanide are also naturally occurring. Yes, I'm very ignorant when it comes to my frog tanks
I know frogs are extremely sensitive so I adopted zero tolerance policy myself (personal preference). Even if the frog survives, it may stop or no longer breed for you or the occurrence of SLS may increase in the offspring. If you use it and if it works and you can still breed your frogs successfully be sure to post back. I'm curious.