To preserve your pumpkins, the first thing you want to do is create a bleach bath to soak the pumpkins. If you are working with smaller pumpkins, you can add multiple at a time.
Add about two tablespoons of bleach and a little bit of dish soap to one gallon of water. The mixture of bleach and soap will be used to clean and disinfect your pumpkin.
After your time is up, make sure to rinse your pumpkins thoroughly, and dry them exceptionally well. You want to make sure that all of the moisture has been removed from your pumpkin as best as you can.
Once the pumpkin is mostly dry (as dry as it’s going to get considering it’s flesh is mostly made of water) apply petroleum jelly to the inside of the pumpkin and any exposed fleshy parts of the fruit (yes, pumpkins are a fruit).