Rotating an Object to its Original Angles after certain distance from ground

So a brief explanation of the project that I am working on is a simple scene where a First Person Controller is standing on a platform that raises them into the sky. When they are at the peak of the lift, about 10 seconds passes and then the lift drops out beneath them and they start rotating as if free falling towards the ground. My problem isn't this, I have this working quite nicely but my problem comes when I want to correct the controllers X rotation so that it is standing straight up again, it doesn't matter what direction they are facing as long as they land on their feet. I have been trying to work with Quaternions to get this to work but it hasn't worked for me at all.. I figured out that I can make the controller 'snap' back into the rotation angle I want but it isn't smooth like I would like (think a cat landing on its feet).

Here is the code snippit I am working with:

     public float RotY = Random.Range (50.0f,150.0f);
     public float RotX = Random.Range (50.0f,150.0f);
     public float RotZ = Random.Range (50.0f,150.0f);
     public float ReturnTo = 10.0f;
     private bool grounded = true;
     private bool straight = true;
     private bool corrected = true;
     private float distToGround;
     public float stability = 0.3f;
     
     public Quaternion origRot;
     private float currentAng;
  
     public bool isRotateX = false;
     public bool isRotateY = false;
     public bool isRotateZ = false;
  
     // Initialization & Detecting if on ground
     void Start ()
     {
         origRot = transform.rotation;
         distToGround = collider.bounds.extents.y;
         collider.isTrigger = true;
     }
     //Boolean if on ground
     bool IsGrounded(){
         return Physics.Raycast(transform.position, -Vector3.up, distToGround + 2.0f);
     }
     
     bool Straighten(){
     return Physics.Raycast (transform.position, -Vector3.up, distToGround + 10.0f);
     }
  
     // Update is called once per frame
     void Update ()
     {    grounded = IsGrounded ();
         straight=Straighten ();
         
         if(!grounded){
         corrected = false;
         //  Toggles X Rotation
         if(isRotateX)
         {
             transform.Rotate(RotX * Time.deltaTime*-1, 0, 0);  
         }
         //  Toggles Y Rotation
         if(isRotateY)
         {
             transform.Rotate(0, RotY * Time.deltaTime*-1, 0);
         }
         //  Toggles Z Rotation
         if(isRotateZ)
         {
             transform.Rotate(0, 0, RotZ * Time.deltaTime*-1);
         }
  
     }
     //Rotate back to original angle
         if(straight && !corrected){
             float step = stability * Time.deltaTime;
             transform.rotation = Quaternion.RotateTowards(transform.rotation,origRot,step);
             corrected = true;
         }
     }

But this doesn't seem to do anything because I always just land and sit on my side.. Am I using Quaternions wrong or does my code just have errors? Any help would be greatly appreciated.