Greetings!
TSA doesn't appear to define the policy of transporting Slow Cookers directly; I think the closest item of match to a Slow Cooker that is on TSA's "What can I bring" list is the Camp Stove.
https://www.tsa.gov/travel/security-screening/whatcanibring/items/camp-stoves
However, there was national news story from 2022 that involved a passenger transporting a large sum of cash packed inside of a slow cooker. According to the story, TSA cleared the passenger of both the cooker and the cash after the local police was notified of the cash stash and ran a check. That means slow cookers should be AOK in both checked and carry-on bags but make sure that it is packed securely so it can withstand travel.
The cooker should not contain any liquids or residue, nor any fuel if gas powered. Power cords and layer items should also be wrapped in bags so TSA can get a clear view of the items. If you're transporting these via carry-on, I would give yourself some extra time and take the cooker out of the carry-on bag and place it directly into the tray when it goes through the x-ray machine to expedite any possible secondary searches as this is not a common item to transport.
Hope this helps!
