sorry for not being here guys, have vet emergency myself, a very crappy one
anyhow
Bowser, your frog possibly have MBD, but it might not, it is not really typical MBD case based on a pictures and a description of what's going on. truly i wouldn't waste time and money for any supplements, baths, etc right now, if it is not MBD you might not be helping with additional Ca, besides if it is MBD you need different dosage and form of Ca
you can give him reptiboost to help him get him a bit more energy for now and please seek vet assistance immediately.

so sorry, you sound like you really care about this frog, i hope vet can help you.