Not on bread... (evidently the Valbazen tastes bad, mine would not take it on bread at all!) Give Valbazen one dose at a time -- down the throat... AVOID THE WINDPIPE (which is right behind the tongue, you will see it when you open their beak)... So... have someone help you.
Take one chicken at a time, out of the coop.. (hoping you can let them free range or have another coop or pen to put them in if you want to keep them contained)....
Lift the head a little... open the beak.. using a measured dropper or more commonly a syringe (no needle).... you put back, to the side, and down the throat...
1/2 CC/ML per standard size chicken
1/4 CC/ML per Bantam or small chicken
orally, individually... giving it to one at a time and then letting that one go or putting that one somewhere else so you don't get mixed up and give a double dose to one, or miss another.
Now... You have to withhold the eggs... no eating eggs, no eating chickens while Valbazen is in them... so... ON THE TENTH DAY... repeat the process.... dose a second time. Then, after a few days, say the fourth day after the second dose, give them some Buttermilk (or yogurt) mixed in with their food...
Wait an additional 14 days.... two weeks.. so.... no eggs/withhold from first treatment ten days to second treatment and then 14 days after that... on the 15th day it is safe to eat eggs or chickens -- a total of 24 days... safe on the 25th.
Watch the poop after the second treatment. IF, if you see tapeworm segments in the poop... you will have to treat more than twice most likely.... and can use Zimectrin Gold -- "pea" size on bread for standard... "BB" size on bread for Bantam... again, one at a time, separating, don't let anyone get a double dose or be missed. This is if you actually see tapeworm segments after two doses of Valbazen... then you would do this "change up" on the tenth day after the second dose of Valbazen and wait the 14 days after that before eating eggs.
Search here on BYC... you can fully trust info from/by dawg53 on "worming with Valbazen", "Tapeworms", "worming with Zimectrin Gold", "worming".... etc. the Search will give you a lot of good info. We all learn as we go, so I like the more recent posts, more recent year's posts for best info.
Good luck. You can do it...
Be careful to avoid the windpipe with the Valbazen... it's a Milk of Magnesia consistency and is available for a bit more at the local feed store... My feed store keeps a VERY LARGE open bottle and sells "CCs" from that... so that I don't have to buy a whole bottle and let it expire before I use it up.
Take care...