cache instead

cache.cs

static public void SetRenderActiveFlagMode( ref GameObject parent, bool mode )
{
        var pr = parent.renderer; // query the component just once!
        if( pr != null )
        {
                pr.enabled = mode;
        }
       
        var pt = parent.transform; // query the component just once!
        int childCount = pt.GetChildCount();
       
        for(int i = 0; i < childCount ; i++)
        {
                var pc = pt.GetChild(i); // query the child just once!
                Renderer rr = pc.renderer;
               
                if( rr != null )
                {
                        rr.enabled = mode;
                }
                       
                GameObject go = pc.gameObject;
                if( go != null )
                {
                        SetRenderActiveFlagMode( ref go , mode );
                }
                       
        }              
}