function my_theme_sidebars_widgets( $sidebars_widgets ) {
if(is_page(28))
$sidebars_widgets['sidebar-10'][2] = null;
return $sidebars_widgets;
}
add_filter( 'sidebars_widgets', 'my_theme_sidebars_widgets' );
ok, I have found a filter for it. I hope this ‘null’ is fine.