Displaying a dynamic sidebar

I've registered a new sidebar for an about section using the default wordpress code

add_action( 'widgets_init', 'my_register_sidebars' );

function my_register_sidebars() {

  /* Register the 'primary' sidebar. */
  register_sidebar(
    array(
      'id' => 'about',
      'name' => __( 'About Sidebar' ),
      'description' => __( 'About section sidebar' ),
      'before_widget' => '<div id="%1$s" class="widget %2$s">',
      'after_widget' => '</div>',
      'before_title' => '<h3 class="widget-title">',
      'after_title' => '</h3>'
    )
  );

  /* Repeat register_sidebar() code for additional sidebars. */
}

I showed the sidebar via a hook element and using the layout to display on the selected pages using the following content:

<?php dynamic_sidebar( 'right-sidebar' ); ?>

It works however I now have the default sidebar showing as well which I don't need.

How can I unregister the default sidebar and show only the about one? Is this the best way to do this or should I do it another way i.e via a template?

I don't want to use a plugin for the sidebars.

thanks

Jon