Did you tell them WHY you were asking? And do you really think they know OR care about your pets? Or do you think they just want to sell their product? Hmm?Don't be so trusting. Understand that they bear no responsibility for anyone using their product in a way that's NOT intended. It's intended for garden use.
No opinion about the "peat moss"- it's not something I use. But the same caveat applies: it's intended for garden use- what % of contaminants are allowed? and what might they be? A gecko is a tiny fragile creature- it doesn't take much to harm it. There's a reason that products sold in pet stores FOR pets cost more- they're responsible for them being safe to use as intended for pets.
And remember- when most people (or companies) are asked about pet safety, they're not thinking about a tiny herp- they're thinking about dogs & cats.
The peat moss might be fine to use -ask Malum Argenteum if this is what he meant?