I don't know anything about the solution shown up above, however, I do know that a tortoise being kept on ground black walnut shells runs the risk of being poisoned. And if the solution shown above kills parasites, that means it's a poison. I would not use a solution shown for human size bodies on a small tortoise unless you get a correct dosage from a qualified tortoise vet.
I thought I remembered that wormwood had some toxic properties because it used to be in an old time alcoholic beverage called absinthe. A quick internet search said that wormwood contains the potentially poisonous chemical thujone. Thujone is a central nervous system stimulant and has been known to cause seizures.
Given this information, I don't think I would keep it in a tortoise enclosure.