I'll look for Valbazen, and if I can't find it locally, I'll order it online. Thanks to both for the advice. It sounds like I give it to them straight, not diluted?
I like to take my scale out with me, weigh each bird, and then draw the Valbazen up into a syringe (with no needle of course) to get the correct dosage. Are you comfortable administering it directly into the crop/esophagus? This is the most efficient method to make sure they get all of it.
See @casportpony 's photos in this thread: https://www.backyardchickens.com/t/745210/how-to-safely-worm-your-peafowl-orally