Epsom will remove excess fluid build up - Epsom is one of the safest, more gentle of the salts and they can live in it indefinitely - safe for plants, etc as well.
It helps us people too with bruising and fluid build up :)
So Epsom should help with the fluid build up, but if it continues then I would look into API General Cure or the Maracyn prodtucts.. popeye usually happens due to bacteria infection or damage. So first thing you want to do is get the swelling down so it doesn't damage the eye any more.