What do they do in the wild, there must be something you can put in the tank that they will gnaw on. A lot of catfish type fish need bogwood in the tank so they can gnaw at it
In the wild their teeth wear down on snail shells... Puffers love snails. In home aquaria their diet frequently don't include enough snails or its thin shelled snails like ramshorns or bladder snails that are easy to breed in huge numbers.
All my tanks have driftwood for my plecos (type of catfish). They don't eat much of it but it is essential for them.
Over time huge pieces of wood get pretty small. They especially love woody cactus parts.


