Jozef Chúťka's blog

Based on profiler (or net.hires.debug.Stats) your Timer listeners doesn’t need to be removed in order to empty garbage collector – the release reference, however it is always a good practice to remove all of them, event those with anonymous functions. Quick proof of concept:

package
{
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.TimerEvent;
    import flash.utils.Timer;

    import net.hires.debug.Stats;

    [SWF(frameRate="60")]

    public class WonderflApp extends Sprite
    {
        public function WonderflApp()
        {
            addChild(new Stats());
            addEventListener(Event.ENTER_FRAME, loop);
        }

        public function loop(event:Event):void
        {
            for(var i:uint = 1; i < 100; i++)
            {
                var timer:Timer = new Timer(100, 1);
                timer.addEventListener(TimerEvent.TIMER_COMPLETE,
                    function onTimer(event:TimerEvent):void{});
                timer.start();
            }
        }
    }
}

Simplest way to remove anonymous function listeners:

EventDispatcher(event.currentTarget).removeEventListener(event.type, arguments.callee);