You can use an oven, just set it on 250 and crack the door open to allow moisture to escape. It will use more energy and will take longer but it can be done. I think it was 12 hours or longer to cook that way. The dehydrator has a fan that blows a constant stream of hot air and it escapes at the bottom.
I laways make a small batch and let my tasters( my boys) try it before making a big batch. Marsha