You could use the sand if you clean it REALLY well, rinsing in R.O. water over and over until it's clean, then let it dry for a long time. Big PITA. The best thing would be to start fresh, and make sure you build up a sufficient sand bed animal population to process all the detritus that makes it's way into the sand. This will keep the waste from accumulating and producing the hydrogen sulfide.

Then you could give the old sand away, rather than just tossing it. I'd bet there's someone in the club who'd take the time to clean it and reuse it.

Good luck!