Put all your movieclips for each scene into an array as you build each scene. Then you can loop through that array and remove them by calling a cleanup function:
function cleanupView():void
{
for( var i:int = 0; i < collectedMovieClipsArray; i++ )
{
var parentContainer:MovieClip = collectedMovieClipsArray[ i ].parent as MovieClip;
parentContainer.removeChild( collectedMovieClipsArray[ i ] );
}
}
the as MovieClip part my not be necessary.