If broken down in some water...instead of dry chunks, it should be alright as an addition to fresh greens or to tie over a day or two if you run out and can't get to the store right away to bet new stuff.

Though not sure what sort of greens are used in tortoise pellets...if mostly timothy hay...may not be all that great for BTS's...(or bearded dragons for that matter). Check the ingredients for what kinds of vegetation is in it.
-----
PHLdyPayne