a farmer friend recommended an herbal worm formula, this one specifically:
https://fiascofarm.com/herbs/mollysherbals.php/categories/herbal-wormer
I gave them the first part of the formula for three days as directed and then did a fecal float. Almost no worms and everyone seems to be feeling better! Obviously, I can't know with certainty what effect it had, since I wasn't able to get a fecal float before for comparison. But I think finding only a handful of worm eggs is pretty good for animals that eat off of the ground. I really like that it is good for both preventing and treating. At first, my chickens wouldn't eat it, but I mixed it into some dried grubs and now they are crazy for the stuff and love taking their medicine. I love it because I don't have to worry about it harming the chickens or the soil life.
You might also check out this thread, if that doesn't feel like a route you want to take.
https://permies.com/t/166564/Guide-De-worming-Chickens-Easily There is some detailed information about how to use more conventional worming solutions in a way that is safe for chickens.
THANK YOU @ Heather Sharpe
this is such good info to consider!!!