I have had the Nesco FD 1040 since 2008 (Amazon) and it has never failed me. I haven't used it much in the last few years though. I used it to make jerky for my kids and treats for my little dog. As well as drying fruits, veggies, and herbs. If you want one to only dry mints or herbs, you may try the paper towel method. Just layer the washed dried leaves between paper towels and sit in an out of the way place for a couple of days or until dry. Store in a jar. The paper towels are reusable for the next batch. I used a cookie sheet to place the layers on to make them easy to move.
I know paper towels are hard to come by but I think clean dry tea towels( the thin flour sack type ones) not terry cloth would work as well.
Worth a try. A dehydrator will do it in hours instead of days though.