The following advice is published by Peugeot on which salt and pepper to use in their grinders.

Peugeot Pepper Grinders

To get the best results, Peugeot recommend you to use only dry, hard, whole peppercorns that are 5mm (1/4 inch) or less in diameter.

Black, white and dry green peppercorns can be ground in the Peugeot Pepper Grinders The pink berries can be ground only if in a blend (max 15% pink) with one of these other peppercorns. Dried coriander seeds are also suitable for the pepper grinding mechanism.

Peugeot Salt Grinders

To get the best out of a Peugeot Salt Grinder , you should use dry, coarse salts with a diameter of 4mm (0.16 inch)

You can use either sea salt or rock salt

NB Peugeot Salt Grinders are not suitable for wet sea salts unless stated - requires a specialist grinder.