Thank you to all who have shared on this thread.
I find it helpful to discuss what is effective for chickens so that those who need information can easily obtain it. It also helps me keep current with the science and real life results.
That is what this forum is about, sharing of ideas and opinions and experiences.
Never be afraid of discussion. As long as we stick to the issue and avoid any derogatory terms (and I didn't see any intended in this thread), in my mind we are discussing an important issue which has varied opinions. And that means others may disagree or have had a different outcome.
I know how very disappointing it is to find a favored method is not really effective but more a result of luck. That has alerted me that it may only be a matter of time before I will have to intervene or that I need to change my approach immediately. Thank you to those who have corrected me in the past.
As most of us are not running true scientific experiments with our flocks, anything we offer is personal experience, which can be very helpful. No matter how much science says it works, it only works if your birds do well with it. And that takes user feed back (Gotta love Amazon shoppers for that!)
I do think we should remember that environment plays a huge factor in helminths (worms).
Someone who has good, freezing, winters, and natural field rotation, will simply not have the worm load in the soil as those who live in more moderate, wet, climates on a smaller lot.
Herbals may be sufficient for the right environment while totally ineffective for another.
I LOVE the idea of herbals. I totally would prefer to treat only with ACV, pumpkin seeds, cayenne, garlic, and wormwood (only my birds won't eat wormwood).
However, I live on a small 1/3 acre lot that has had chickens for a lot of years. I cannot field rotate well (though I try to seasonally scoop out runs and add fresh which is almost like field rotation).
I also have a mild, wet climate that is ideal for worm growth. I can at best keep worms somewhat at bay, for a time, but must resort to meds or my birds' health sorely declines. My SIL, an organic farmer in the deep south, agrees. His environment, even with field rotation, tends to battle parasites because of the climate and wild life present.
It helps to consider your situation, your environment, your climate.
To help make my choices, I do rely on science as I want to see controlled evidence that something is actually effective before I put my hard earned dollars towards it. However, I also enjoy hearing the experiences of those who have closely witnessed the effects of alternatives.
So thank you all for sharing to help us all improve our knowledge base.

LofMc