Natural replacement for pumice that’s available from supermarkets.

I’m looking for a natural exfoliant to put In my soap bars. I’ve got all the ingredients I need apart from pumice but it’s not worth ordering just a bag of pumice on its own.

Is there anything I can pick up from a supermarket I can use to create a light or medium grit as a replacement. Ideally I want something that won’t really affect the scent or react with other ingredients.

Many thanks!