Both excellent questions! I forwarded it to my main toy reviewer and he said this in response:

“Unfortunately there is no option to toggle between the two functions, it is simply on or off. I have left it in the toy for as long as an hour though, if it is plugged in it will turn back on once it has cooled a bit if you want to use it longer.

I have used it regularly, and always use it with onaholes I don’t use frequently and will be in storage for significant time periods before further use. None of these toys have ever had noticeable bacteria / mold and I always check before using them again. Whether that’s due to the UV light or just good cleaning, I can’t be sure because I’ve never gone long periods without using the Steri Warmer.”

I hope this helps!

Have you been using it consistently over the years since reviewing? Has it anecdotally worked to delay the onset of bacteria buildup?