There are several different opinions on worming. Some folks never worm. Others worm only after a positive fecal float at the vets. Some folks go natural, others worm routinely.
I chose to worm once a year with a broad spectrum wormer. I worm my dog and cats once a year, so why not my chickens?
I see very little value in wazine. You go through the whole wormer process, including the egg withdrawel time and it's only good for roundworms? If I'm going to worm, I want to catch all the pesky little boogers, not just roundworms. There's an argument out there that says you should not hit them with the stouter wormer first, since it can cause a blockage when the chicken tries to pass all the dead worms at once, but if I'm worming once a year nobody should have a heavy load of worms to start.
You should not use any of the broad spectrum wormers in the febendazole family while your birds are molting, as it's been said to cause feather defects.
Last year I used albendazole (valbazen), but my birds weren't molting. This year I wasn't going to worm, having decided to skip to every other year, but I had a hen acting poorly so I went ahead and wormed everyone.
Since I had a cheap (as in free) source of ivermectin pour-on, that's what I used this time around.
Since most of the broad spectrum wormers are used off label, i.e., not labeled for use in chickens, there is no listed egg withdrawel time. My research into others experiences suggested a two week egg withdrawel, so that's what I went with.
Wazine, if I'm not mistaken, says in its directions that it's not to be used in egg producing birds, but again my research shows most folks waiting a two week period.
