Food was left in Instant Pot for a month and it grew mold. Is it safe to use it after cleaning?

While the other answers here all suggest overnight soaking with chemicals and/or high-heat treatment I would say that cleaning it thoroughly is enough. Get all that you can out of it, then clean it with soapy water. If you still have stuck on rice soak it with cold water for awhile as that will help the starches release. Once you have all the rice out then clean it with hot soapy water and you're good to go. A spray of anti-bacterial cleaner inside before wiping it out and rinsing wouldn't be a bad step, but remember you're going to be pressure cooking stuff in there, that's going to kill anything that could make you sick. Remember to try and avoid scrubbing as you could damage your non-stick surface, multiple soaking is your friend here. If your pot is stainless then scrub away.

What I would be more concerned with is what may have gotten not in the pot itself but the cooker unit, for instance spores and bacteria. I would use an old toothbrush and anti-bacterial spray to get into all the nooks and crannies like hinges and seals, and don't forget to clean the lid!

Honestly? I would scrub the pot, and then toss it in the dishwasher and be done with it. So long as the smooth surface (notice I did not say scratched up) is clean meaning no visible soil, then running it through the dishwasher with its hot water, detergent and possibly drying cycle will be more than enough. It's not like you have some biochemical experiment you need to avoid doping. Just practice good hygeine with your cooking equipment and you'll be fine.

Water and soap (only) is probably a bit less that I'd suggest for this problem.

Get the bulk moldy glop out and wash with water and soap, then rinse.

Fill with Water and chlorine bleach, and a nice long soak (overnight, or even a few days) would be one further component of a through cleaning.

Rinsing very well (do not combine disparate cleaning chemicals) and then using baking soda (sodium bicarbonate) with adequate boiling water to fill the pot would be another step - let that soak overnight as well.

Rinse throughly, wash again with water and soap, rinse throughly again, and give it the "sniff test" - if it doesn't smell moldy, and it looks clean, you are good to go.

I have encountered similar problems a few times. My approach is:

• Scrape or otherwise remove as much as possible.
• Spray with bleach-based kitchen cleaner which I have anyway (meant for worktops and sinks, it warns about rinsing well before contact with food) and wait at least a few minutes .
• Remove the rest by scraping/rinsing (repeating these steps if necessary).
• Rinse well
• Put through the dishwasher (including non-stick: I've only found the dishwasher to make existing damage worse, not to cause new damage). This is one time I use a 65 or 70°C wash rather than my usual 50°C eco wash.

Instead of a dishwasher you could hand-wash as the main purpose of this step is to remove all traces of bleach.

Don't get so anxious about mold, mold is not necessarily as frightening as people seem to think. To generalize, the truly dangerous mold comes from rotten meat, the mold from rice, bread and vegetables is gross, but much less dangerous. You do not need to take any extraordinary precautions. Wipe and wash out your pot, use dish soap, and smell it. If it no longer smells like mold, your job is done. If it still smells like mold, use a cleanser, and wash the cleanser off thoroughly. You can also simply boil water in the pot, and that kills all mold as well. Dishwasher shouldn't be necessary at all.

Your nose is the tool you are endowed with to detect dangerous mold, if it doesn't smell awful to you, then it's fine.

Throw it in the garbage and buy a new cooking pot.