AddExplosionForce not working

Well, I’m trying to add a explosion force when I release the mouse button, but I have two problems: 1- The joint i’m creating is not destroyed properly and 2- The addexplosionforce doesnt work to me :'(.
Here’s my code:

using UnityEngine;
using System.Collections;

public class holdBall : MonoBehaviour {

	private bool hold = false;
	private bool criou = false;

	void OnCollisionEnter(Collision c){
		if (Input.GetMouseButton (0)) {
			if(criou == false){
				var joint = gameObject.AddComponent<FixedJoint>();
				joint.connectedBody = c.rigidbody;
				hold = true;
				criou = true;
			}
		}
	else{
			if (hold == true) {
				var fixed_joint = gameObject.GetComponent<FixedJoint> ();
				Destroy(fixed_joint);
				hold = false;
				criou = false;
			}
		}
	}
}

I don’t see anything about AddExplosionForce in your code, so I won’t comment on that.

As far as your joint destruction issue is concerned:
Destroy is not guaranteed to happen immediately. Or even soon. Try setting the joint’s connected body to null to give the impression it has been removed. Then, if you really need the joint to go away right now anyway, try using DestroyImmediate.