I discovered this by accident and would recommend to anyone.
All you need is an acorn squash small enough to fit inside your crock pot, or, rather, a crock pot large enough to accommodate an acorn squash. The smallest size crock pot will likely be too small, but nowadays they make them plenty big. Acorn squash is dark green and has ridges.
Remove the supermarket label, if there is one. If there’s a stem, remove that, too. Just snap it off. Turn the acorn squash upside-down, that is, stem side down. With a knife, poke some holes near what is now the top.
Place the acorn squash inside your crock pot. Fill with water alongside the squash but don’t fill all the way up. Plug in your crock pot and turn on to the high setting. Now, you might as well forget it is there. I did!
About an hour later or maybe two, your squash is all done! Remove with wooden spoons and be very careful. Or use an oven mitt. Place on a cutting board and cut in half. Don’t burn yourself in the process. Scoop out the seeds. You’re done.