I would never use any kind of BBQ material to give my chickadees a dust bath. I have used a big shallow planter for small chicks and my hens took it over. I put a bit of sand, wood ash,dirt, and some poultry powder to keep lice off of them. YES chickens get lice. I used to sheep dip my large flock 2 times a year. Also a spray with mouthwash can keep any bird pest free. (I usedto be known as the Oalaska Chicken lady. And I had a 150 parrots. My birds always stayed healthy and happy. Have you ever fed your chickens leftover spagetti ? Its funny, they think its worms. Once in a while I stick a few yogurts in the coop. its good for them. Have fun, feed them leftovers even with meat. Its good protien for them. Now ... Chehalis chicken lady with a few babys.(gettin too old)