I know the topic is sort of old but...
I use my oven for all sorts of dehydrating. I make sure my pan is lined with parchment paper or use a broiler for slices. I heat the oven up to it's minimum (mines 250), kill the heat, and pop the sheet in. After the oven has cooled enough that the sheet is handlable with my bare hands, I give the stuff a shake, stir, flip, whatever and redistribute over the sheet as I heat my oven up to minimum again. Then the sheet goes back in, and dries/cools. I repeat as often as necessary to dry the stuff.
I've used this method to dry all sorts of herbs, minced mushroom, garlic, and onion, citrus peels and zests, apple, pear, and tomato slices, small whole hot peppers, split jalapeno sized peppers. I've done shredded carrot, celery, and potato too. With delicate herbs, I've found it best to crack the oven door with a spoon during drying periods.