Incidentally, to "sleep with the fishes" is Godfather-metaphor for having been waxed; thus, it would work just fine for Duncan. Lucca Brazzi was garroted, but the medium was not the literal message in that case.
There was a film-noir gangster version of Macbeth in the 50s. I've seen bits of it. Made in the UK.
http://www.imdb.com/title/tt0048230/