Making a surface have accurate friction

Got an issue I've been wracking my brain trying to figure out. I'm making a billiards game, and the balls need to have an accurate way of coming to a stop, so I tried playing around with the drag and angular drag properties in the RigidBody component, but never came up with anything even close to what I wanted. I then tried using physics materials, but I never saw that have any effect (I think its because physics materials only stop lateral motion, not rotation).

So, I am now trying to stop the balls motion by getting its motion vector and applying a constant force in the opposite direction until the motion stops. Right now, the pool balls will spin and move wildly around the table a moment or two after the scene starts. Below is my code, and any help would be greatly appreciated.

 using UnityEngine;
 using System.Collections;
 
 public class PoolBall : MonoBehaviour {
 
     private Rigidbody rb;
     private ConstantForce cf;
     private Vector3 lastPos;
     private Vector3 currVeloc;
     private float percentageDifferenceAllowed;
     private PoolBall pBScriptGetter;
 
     // Use this for initialization
     void Start () {
         rb = gameObject.GetComponent<Rigidbody>();
         cf = gameObject.GetComponent<ConstantForce>();
         lastPos = gameObject.transform.position;
         pBScriptGetter = GetComponent<PoolBall>();
     }
     
     // Update is called once per frame
     void Update () {
         Vector3 currVeloc = rb.velocity;
         if (lastPos != gameObject.transform.position)
         {
             cf.relativeTorque = -currVeloc * 0.5f;
         }
 
         pBScriptGetter.CompareVectors(lastPos, currVeloc, 5f);
         lastPos = gameObject.transform.position;
         
         
     }
 
     void CompareVectors(Vector3 Vec1, Vector3 Vec2, float tolerance)
     {
         if (Vec1.sqrMagnitude - Vec2.sqrMagnitude == (Vec1.sqrMagnitude * percentageDifferenceAllowed))
         {
             cf.relativeTorque = Vector3.zero;
         }
     }
 }