I wish those old posts would disappear, lol. Pick one wormer and use it twice, do not use one then the other.Actually when I was looking at the treating for worms, I read alot on BYC and its recommended to start with Wazine because it gets rid of the roundworms first and then followup with something like Ivermectin to kill all other worms.
Another thing to note is that ivermectin is actually not a very good poultry wormer, so I would suggest never using it for worms.