Normally before plating there will be a called out for grit blasting at a required pressure and than you need to use chemical to clean the surface e.g. sulphuric acid (dipping method)for not more than 30 seconds, rinse and than plate.
Important is that your sieve must be able to remove the broken shots.
If that is a heat treated part my advise is to grit blast the part before shot peen.This will reduce the scales from embarking into the parent metal.
You may want to try this solution.
Regards: Tessensohn Albert
