Honestly, I really don't see a problem with this. It is transparent, yes, but you could always put some substrate overtop it or something. There seems to be a large enough opening for airflow that I don't see an issue with it. If you need to get your snake out... for whatever reason... just tip the jar, let her/him slide down, and there ya go! Glass is very sanitary as well, so I don't see how it would be an issue for the snake (as in, being uncomfortable or anything). Over time I think there would be bacterial build-up in any wet/damp moss, no matter the conditions.

Creative use of a jar best of luck!