Years ago, someone brought my mother a Canada Goose egg, can't remember why or how they got it, it was already partly thru its incubation period. She hatched it out in her electric skillet, back then I don't think glass lids were available. She kept it on lowest heat setting, put a small thermometer inside, and kept a sponge moistened in a glass dish. She removed the lid to turn the egg. The goose hatched and then followed my mother everywhere, she got it a small childs wadding pool and had the goose for quite a long time.
Well, we did it in 1973 with duck eggs. Someone gave my mother an electric skillet and she didn't like it, so she gave it to me and my wife. We were unsure how to use it; everything seemed to stick to it. That was before teflon. So we decided to hatch out some ducks with it.
Duck eggs take four weeks, and we didn't plan well. We had a wedding to go to back east in that last week. So my father in law took the skillet and eggs to his barber shop and set it up for that week. He rotated the eggs and spritzed them to keep them damp. They were wrapped up in barber shop towels which he changed regularly.
They hatched out the day after we got home.
Sadly, one of the ducklings fell out of the skillet and then crawled under it. When the darn thing kicked on again, it killed it.
My mother used to talk about how they used to hatch out eggs in a manure pile. I guess it worked. Also, my father talked about a well endowed French lady that hatched eggs in her bra.
So, I guess there are a lot of ways to incubate eggs. We didn't know what was involved in the process. That shows the constructive value of ignorance.
Give it a try; what have you got to lose but a few eggs. Just be sure and turn them and keep the humidity up. You might want to run the thing for a day or two prior to putting the eggs in. Try and get the temperature steady at about 101 degrees or so.
Can't remember the company, but they used to do this back in the 60? I think to show how the temperature held steady on their skillets. Most time they did a demo in a store and the eggs were hatched as part of the demo.
Doubt a crock pot would work unless is was one that didn't shut of after a certain amount of time. Do they still make those?