So to get a better understanding on why this product seemingly worked for Randy and isn't working well for waster I took a look at randy's thread. I first have to say good job, your little guy looks much better. unfortunately, I don't feel the metro/prazi had a whole lot to do with it. Why this medicine states it works on anchor worms/fish lice is a mystery to me. I have found no proof of its efficacy in parasitic crustaceans in any of my textbooks or even on VIN/VSPN website (private veterinary form). It's labeled as a general cure for a reason I guess. I honestly think that randy's success was due to removing his axolotl from the infected tank filled with probably thousands of free swimming larvae. Decontaminating the tank is what did the trick. Imagine they are like fleas, adults are only 5% of the population the rest are eggs and larvae. And for the adult anchor worms, well after they mate the female attaches, lays eggs, then dies anyways. Randy's axolotl probably wasn't in the treatment tank long enough to have mature larvae reattach.
Some examples of IDI drugs with the proper mode of action: Diflubenzuron (dimilin), Cyromazine, VIN states success with lufenuron in tadpoles, I've heard proform-LA is safe on amphibians but the man that dispenses it will not tell me the active ingredient so I have no idea other then it is an IDI.
Just trying to share some knowledge, when my axies get sick I'm usually on my own to do all the research and plan the best treatments. I work at a vet office and my Vet doesn't treat reptiles or amphibian so i'm left with minimal guidance (he knows I like a challenge). I have to add anchor worms are no fun! I'm glad my ordeal will soon be over and I hope yours will too.