You are absolutely right, neither cedar or pine is suitable substrate for anyone, I use aspen and only for snakes that dont need high humidity.
But for frogs???? Are you kidding? Where did that idea came from, that is very bad , change it to exo earth/plantation soil ASAP and if you really keep in on that substrate do you want to post answers for trouble in the enclosure here, I kinda think you may need some advise