Adding dust and scratches - can't figure it out

Hello gentlemen,

I've tried using the dust and scratches filter on a piece of video,
and I just don't know what settings to use, to get it to look like
dust and scratches.

In Windows Movie Maker, you add the filter on, and right away you see the effect, and it is very pronounced, it looks like an old film.

Now in PP, I just don't get this effect at all, no matter how much I play with the "radius" and "threshold" settings I don't see anything like dust and scratches giving it that old kind of feel.

Any help much appreciated.

Dave.