Hissing cockroaches possibly poisoned?

[FergusFerguson]

First time user here!

I have two male hissers, one of which I just got. As of this morning, they've both been acting strange -- they're very weak, they have a really hard time crawling, their legs seem to be splayed out at awkward angels, and sometimes their abdomens seem to be heaving. It seems to me like they've both been poisoned, and I'm not sure what caused it? Perhaps insecticides are the cause and I should have rinsed their food off more thoroughly, but I've never had a problem with that before. While I was picking up the new hisser, I also got some new driftwood, repti safe dechlorinator, and repti calcium for them, I don't know if that might be the culprit either? I poured boiling water on the driftwood to disinfect it and the person at the store said the repti safe and repti calcium should be fine for invertebrates, but I can't seem to find much on the subject online.

I'd really appreciate any insight onto whats going on or advice on how to proceed, I'm quite fond of these guys and I'd really like them to pull through.

[Crazy Bug Lady]

I'm not sure about poisoning.  A good rinse usually does the trick for removing poisons for me.  I hope your boys pull through.

[Allpet Roaches]

I know if you feed them punky (barely starting to rot) coconut you can kill 90% of them, all the adults.

[Portentosa]

I have some hissers in the same boat, they aren't moving normally but convulse, sometimes flipped on their backs until I right them and their antennae are limp. I guess it must have been the lettuce I gave them not being washed well enough? I hope it's not something contagious to the healthy ones. It's been about a week and they have neither died nor improved. Any chance they'll recover or is there anything I can do to help them?