Sorry, no crouton recipes in the dehydrator book, but there may be something in the Excalibur manual. Bread cubes would dry nicely but you should not use any oil and the addition of herbs may not stick. Perhaps that is why there are no recipes in the dehydrator book.
I use the oven since I use olive oil and herbs and a higher temperature (350-375 F) to bake and crisp.
PS - I'm very envious of your Excalibur. I only have the American Harvester FD50 GardenMaster, but I do have about 12 trays, most yellowed from age and use.
UPDATE: Here's an "oven" crouton recipe just in case you are interested.
Croutons
10 slices bread -- heels are fine (homemade or store bought)
1/2 teaspoon basil
1/4 teaspoon oregano
1/4 teaspoon garlic powder
1/2 teaspoon celery salt (or 1/2 teaspoon salt -- and 1/8 teaspoon celery seed)
1/4 cup oil -- (1/4 to 1/3)
First make 2 piles of your bread. Using a very sharp, serrated knife, slice them into small cubes. I make 5 cuts each direction, one down the center, and two to each side, but you can do it the way that works best for you. Place all of the bread cubes into a large bowl.
Sprinkle on the seasonings. Toss briefly to mix in the seasonings. Next dribble in the oil somewhat evenly. Now gently toss everything together. The oil will help the seasonings stick to the bread and also make the bread crispy without actually having to fry it. Spread the croutons on a large cookie sheet, use two if you need to. Bake them at 350 degrees for about 20 minutes or until they are crisp. Remove from the oven and allow to cool on the pan. Store the croutons in a plastic bag, or resealable container. Serve on salads, or tossed in omelettes, or on top of plain spaghetti and Parmesan cheese.
