No. Hermit crabs should not consume stress coat.
Additionally, there is no hard evidence that adding stress coat to bath water benefits the hermit crab. If you prefer to use stress coat it should never be added to the drinking water in your crabitat.
If you do add stress coat to your hermit crab bath water, do not use a separate dechlorinator in the water. The stress coat acts as a dechlorinator. The stress coat will not be able to bond if you use a separate dechlorinator.