I was researching all this a while back. Unfortunately I haven't actually started my rotation yet. However, this is the information I found through some other threads.
Please remember, this is only a suggestion from other threads and any medicating you do is at your own risk.
Here are some other things people said I found interesting:
For new birds/babies:
My first worming I use wazine and then during the necessary re-dose (you must always repeat piperazine worming) use the stronger wormer. Then I use the stronger wormer twice annually for those birds thereafter
I worm chicks at four months with ivermectin and put them in rotation with the adults for twice yearly. If on old ground start with Wazine
Fecals:
Alternatively, there are places online to which you can send fecal samples if you're interested. Foy's offers the service. (Call ahead to make sure they do fecals for poultry):
http://www.foyspigeonsupplies.com/catalog/8000
A nice gentle flush (not a treatment strength, but more of a post-worming flush) is a tiny bit of molasses in water, mixed with applesauce, a little cooked oatmeal, yogurt, and some crumbles or egg mixed into a damp mash. The applesauce's pectin gently cleanses the digest tract while also making good bacteria "happy", the molasses also makes things flush ou ta bit, the yogurt replaces the good bacteria in the digestive tract, the oatmeal sooths, and the egg - well they just like it. Do it only one meal.