I remember someone else buying & using a steam cleaner- never tried one myself, but be careful that you don't warp plastic enclosures (tubs especially, but maybe even PVC-?). Otherwise, in terms of being non-toxic, it's a good idea. Let us know how that goes, if you do try one?
You can wipe the whole enclosure with white vinegar, full strength, but it's no fun having to rinse that much- & it's definitely irritating, so for me, it's just for water bowls. Or hides would be OK too.
Use white vinegar for things that are easy to rinse. Vinegar is not toxic- just irritating.
I'm glad you think in terms of what might be toxic- it's important for our own health too- don't assume that just because it's sold, it's safe- read the fine print & search it online.Herp pets are so much more sensitive & vulnerable than we are, since we're so much larger, and since any remaining chemicals will be breathed-in by our pets- especially since most of you use enclosures that restrict most of the air-flow.