Prevent rigidbody being affected by character controller

There are potentially 3 ways I've thought of which I've put in bold, that if I figure out just one of them, then my stuff will work.

I'm trying to write a script so that my character can be crushed by objects. I'm using a CharacterController for what I'll call the 'controller' and the objects crushing him are rigidbodies which I'll call the 'crusher'.

The crusher is currently using a non-kinematic rigidbody, gravity disabled and constraints set to all. I can detect being crushed perfectly fine, the problem is when my controller, say jumps, it pushes the crusher away making it fly off. How can I stop a character controller from moving the rigidbody?

I've tried setting rigidbody.velocity = Vector3.zero; every FixedUpdate. This stops the crusher flying away but you can still notice resistance.

Now if I make crusher a kinematic, it works fine, but I lose the ability to use OnCollisionEnter() and therefore the way I'm detecting the player being crushed. Is there anyway to detect a collision between a kinematic and a character controller without using OnControllerColliderHit?

Would attaching a rigidbody to my controller give me back OnCollisionEnter?

Finally I thought about using a trigger on the crusher and using OnTriggerEnter, but if I jump I just pass through the crusher. Is there anyway to prevent a collider passing through a trigger? I tried attaching a trigger to another rigidbody as a child but I still passed through it most of the time. Would separating them and position them at same place through a script work?

Cheers for advice.

-edit-

Got a video of current issue.

http://bovinelabs.com/crush/crush/

This is using a rigidbody kinematic and a separate trigger

The crusher moves on FixedUpdate() using

rigidbody.MovePosition(rigidbody.position + _direction*Speed*Time.deltaTime);

CharacterController is a heavily modified version of the FPSwalker to allow stuff like wall jumping, but I do not believe any changes would affect this.

Notice it only really does it when it's going down, and I'm moving up

Use a trigger to detect crush, and then have a kinematic rigidbody collider to prevent your character controller passing through your object. In short, two separate objects (preferably set to ignore each other).

If you make the trigger a bit smaller than the collider, you can have some 'safety' region, so you can't jump into the crush trigger.

To stop your character from pushing the crushers away you could always make the weight of them huge compared to the characters str.