I NEVER WOULD. I'm just telling you what you may hear as advice from other readers. IMO, it's not uncommon for a low parasite load. Our society is germophobic, and that same fear also applies to parasites in animals. I see to it that my birds have access to free range. There are many anti-helminthic plants out there that they will self medicate with as needed. Some include garlic, oregano, pumpkin seeds, wormwood, stiff grass blades. If your flock is regularly culled to remove the less thrifty birds, you may never see signs of worms. If I DID have a problem that was not solved by culling, I might use garlic, pumpkin seeds and Basic H soap. Soap has been used by farmers for hundreds of years. But it wasn't the garbage we use today when we wash dishes (all the antibacterial chemicals in it). As a matter of fact, the farmer's wife would always dump her dish pan outside after washing dishes. That soap nourished the plants it landed on, and the little bits of soapy food at the bottom of the pan was eagerly eaten by the chickens.