I have never used either of those...I made the chick bator (styrofoam) that was documented by MissPrissy....it works great! You can click on the "Search" heading at the top of the page and search for skillet or crock pot to find what others have done...
I tried both of these when I fried my hatching eggs (my own, at least), putting in the dead eggs to try and stabilize temps. I know people have done it successfully, but I couldn't. Both attempts ended way too hot, and with me unable to adjust it better. You could try it with a few unimportant eggs as a dry run and see if either of yours will maintain good temps before putting in hatching eggs.
I tried making one out of a crockpot and a dimmer..
Not sure if it was the house wiring or what..But Whenever I would use a major appliance, it seemed to throw off the dimmer..It would either go totally off, or go too high..
I'm now working on a 'bator out of an old igloo cooler
You can buy a still air incubator for under $50. Why waste your time trying to hatch eggs in kitchen appliances? It's got to be frustrating because I just don't believe it's possible. If you don't have $50 save up until you do.