Seriously Wondering if I am Cursed

[chairman]

Sounds like you've had some bad luck. Good on you for sticking with it and trying to get it right.

It is possible that your overhead light was dehydrating the snakes. You said the heat pad was on a thermostat but not the light. Maybe more so because I think they recommend only offering rosy boas a water dish once weekly or something like that?

Another similar possibility is that the cage was in direct sunlight and overheated that way?

Chemicals would be the next most logical, though I wouldn't suspect the bird cleanser you used to be the culprit. I use F10 or diluted chlorhexidine to clean my enclosures when more than spot cleaning is needed. Other household chemicals that may cause harm include smoke (tobacco, marijuana, incense, etc), essential oil diffuser, bleach or ammonia used in strong concentrations in the same room.