Shredding rubberflipflops

Hi everyone,
has anyone tried to shred rubber materials (or more specifically: flipflops) in the plastic shredder?
I was asked to build a rubber shredder for OceanSole, a flipflop recycling company in Nairobi, Kenya. Any ideas/tipps?

We are about to build the plastic shredder in Nairobi and I will definitely try it out, but maybe someone can already tell about experiences with this?

Thank you!