My pet monkey has heard of people doing this before with some success. What they did was take delsym and dilute it with about one liter of water per bottle. Wait for the polistirex to settle to the bottom, then siphon the extra water off until you're left with murky dxm
-water. Next mix one part dxm-water with two parts lemon juice. (Try to find lime juice as it has a lower Ph, or better yet pure citric acid.) Then down the whole thing.
Probably wouldn't work as well ad Hbr, but it hits faster than delsym alone.