1. RE: Seeing alot of worms in poop: Not necessarily. Most of the time worms are absorbed as protein in the digestive tract. It also depends on the worm load. That's another reason why I dont use wazine or any wormer that has to be mixed in water. You dont know if your birds drank enough of it to be effective. Also if your birds are lethargic and sick due to worms, they wont drink the treated water. Additionally, if it's cool/cold outside, chickens drink less water. Same is true for antibiotic soluable powders.
2. Yes, you can put valbazen on bread. You'll have to give a piece of treated bread to each chicken one at a time, if you dont, the others will steal each others bread and you wont know which ones got properly dosed.
You can have someone hold the chicken for you. Preload a syringe (without needle) with 1/2cc valbazen. Pull the hens wattles down and her mouth will open. She might struggle but hang on and she will tire. Then squirt the liquid in her mouth and immediately let go of the wattles so's she can swallow the liquid on her own. If you dont immediately let go of the wattles, she could aspirate. Then there would be big problems. Practice without actually giving a hen the liquid valbazen...you'll get the hang of it and do just fine.
