I'm not sure if ASF can get wet tail, as it is generally a bacterial infection in the digestive tract. I know rats do not get wet tail, but hamsters do.
If you want to serve beans, I forgot to mention that they have to be cooked dry beans, not raw.
You can use any type of cooked dry beans (such as pinto beans) in the diet (canned is fine). Give a variety of different beans to take advantage of their different nutrients.
Here are some ideas from the Rat care guide. Assuming ASF are still rats, I would imagine these are all going to do well with them.
I suggest trying something new each week, see how they react to it, any digestive problems, skin lesions, bloating, lethargy etc. You always want to monitor how new foods sit with them.
This along with a staple kibble to be eaten freely like Mazuri 9f or Harlan should give you some healthy and happy ASF.
Wild & Brown Rice
Tri-Color Pasta
Toasted Unsalted Soy Beans
Toasted Unsalted Chick Peas
Hulled Unsalted Pumpkin Seeds (not always, and 1/2 portion)
Rolled (roasted)Oats
Bran Flakes (cereal)
Shreddies (Wheat Chex)or Cheerios
Regular Granola
Hard Wheat Kernels
Soft Wheat Kernels
Spelt Kernels (when I can find them)
Rye Kernels (when I can find them)
Rye Flakes
Wheat Germ
Raisins
Dried Cranberries
Soy Nuggets (3 portions or more)
Pot Barley
Split Peas
Lentils
Flax Seed (1/2 portion)
Dried Apple
(Canada) Vector cereal (2 portions)
or
(USA) Total cereal (2 portions)
popcorn kernels
unsalted corn (unsalted toasted corn sold as a people snack)
Supplement diet with fresh fruits and vegetables.
Rat Guide- diet