Can you post a picture of the worms in the poop? You cannot get flubendazole in the US. The ones I posted about in my last post are available, and do not affect the eggs.
What wormer are you talking about? Most wormers that I would use—Valbazen or Safeguard are very safe to give to a broody hen. There is a 14 day egg withdrawal time. She won’t be laying eggs while she is broody.