I have used clout that is made by fritz but recently discontinued and I have also tripled the recommended dosage of praziquantel for treatments every 5-6 days for 4 weeks with success, never doing a water change in between treatments for whatever that’s worth.
Man, I have had the opposite effect. I've had fish start dying on me if treatment gets to a full dose!
Maybe I should have started with a FW bath or something first to knock off a lot of the ones in the gills.