deworming is done in our farm by giving them a capsule brand every 2 months. We give 1 tablet the first day, and then another tablet 10 days after to make sure than if any oocyst was left in there, the second tablet will get them. The capsule we use is from a Rio Linda vet supply in Oklahoma and it also gets rid of eyeworm and tapeworm. We buy them in granules and we encapsulate ourselves.
delousing is just giving them a bath with "washout" to get rid of skin and feather parasites. We also rinse them on water with mane and tail horse shampoo to add lustre.
hope this helps.