Updating Dynamic Mesh's Collider is Too Slow

I'm making a pottery application. The pot is very large, it's 31400 verts and I'm sculpting it's mesh each frame. All of that is working out well. Now I want to add some physical properties to the pot's mesh so my hand does not go through it.

 //in a nutshell, I blast my verts into Unity, from a magical DLL each frame
 //something like this.
 myPotMesh = MagicalDLL(myPotMesh);
 
 //and each frame I set the Mesh Collider to that mesh
 myMeshCollider.sharedMesh = myPotMesh;
 
 //but it will still only reference the mesh that was set the first time around, despite me setting it each frame!
 
 //So instead I try also resetting it each frame. This works, but is very slow!
 myMeshCollider.sharedMesh = null;
 myMeshCollider.sharedMesh = myPotMesh;

The Mesh Collider must make a copy of that mesh and then no longer refer to it, despite me explicitly setting it each frame.

Any suggestions would be appreciated. I'd like the mesh collider to refer to a mesh without having to make a copy of it, if it's possible.

Thank you