Thanks for your response. I would appreciate any help in an alternate solution. Here's what I'm trying to accomplish. So I bought the female model, which doesn't have the waistband. I added the waistband (which is a real product from which I modeled) by creating three cylinders and colliding them with the model. What needs to happen is that we see the model's stomach shrinking once the waistband is in place. I first created a fat model by duplicating the purchased model and using the Inflate tool in Sculpt to make her stomach bulge out. Then I collided the waistband. Then I thought I could just combine those meshes, and use the Flatten tool in Sculpt to flatten the belly that I had already Inflated. That didn't work so well, and I abandoned that method, which is why it took me this long to reply to you.
The new method I tried is to use the original model, which is skinny, collide the created waistband with that, and then Pose Morph between the fat and skinny model to create the shrinking belly effect. The Pose Morph didn't work. It gave me heavy distortion on the target model. I imagine it has something to do with the collided waistbands. The models and the waistbands have the same subdivisions, but something about the Collision Deformer is not allowing the Morph, in the same way that it prevented sculpting in my first method.
How would you go into achieving what I'm trying to accomplish? Thanks so much for your help.