Do this with a couple of "perfect" pumpkin shapes. Create a way to 3D print these as a mold to make your own "pumpkins" to be carved without all of the mess and able to last longer through the season. No more petroleum jelly, no more soaking them in the tub.
It's a plant. Think of it as a cut flower. After cutting open a pumpkin, they are obviously no longer sealed. They start to dry out. You can rub petroleum jelly all over the carved sides to help slow down the drying out. You can also soak them in the tub, and they will pull in some of the water to help them come back into shape.
There's all sort of things you can do to prolong things once they've been cut/carved/etc. My mom was a florist and designer. I've been in/around productions requiring things to be preserved so items can be kept around as long as possible. You just kind of pick up a thing or two
There are also various chemical solutions that you can put on the pumpkin to make it last longer. However those are not recommended if wildlife is around. Moose, in particular, love pumpkins. I suspect deer are the same.
Sure the deer, but I don't want that stuff around me. Better living through chemistry is something I'm trying to avoid now that I can make my own choices about what goes in, on, or around me.
