What exactly do you want to delete? The parent object? The related objects? Only the relation between the two?
I see more issues here.
You pass a variable $id in the action method, but this value is overwritten by the $id used in your foreach. Is that intended?
And what is that exactly? It looks like an array with id's of some sort, but on the first find you do a redirect, which means you no longer process all others?
Perhaps explain exactly what you want to do, and what the input is (both from the URI and from the post).