https://www.backyardchickens.com/t/727707/ivermectin-pour-on-dosage
I finally found this dosage rate for the ivermectin pour on. I normally like to follow information from real science, like university studies that have proven what works and what doesn't. Because there is so much mis-information out there! But this is an off label product use, so I don't think I will be finding that for this product. Although it is off label, I have seen charts where dosage rates are listed for the injectable Ivermectin. And years back when we raised tropical birds our vet dosed a cockatiel for us to treat for mites with the injectable ivermectin. It worked perfectly. And I think that the use of Ivermectin pour on externally on chickens is off label only because there isn't any money in it. There is no pay off for doing the studies etc.
If there is a 10-14 day second treatment and then a 10 day (at least) withdrawal that takes up a lot of time. But for the kids show poultry breeders (that we don't plan on eating, lol) It is worth it to keep them healthy and not being subjected to their health being compromised by any worms or mites. I inspect our chickens VERY regularly and have not seen any signs of mites. But worms........well, chickens eat dirt, and sometimes taste a freshly laid steamy turd that the hen next to them just dropped. So I'm pretty sure that all of my chickens need to be wormed at least once a year. I didn't used to think so, but after this many years I really do. Now that we have been worming they are just so much healthier and their feathers look great, body weight is up overall. Happy Chickens.