Thanks Snoopy. Have seen a hand held one on eBay for around AUD $40, and probably wouldn't want to pay too much more than that.
I found that the sieve didn't really clear the sand very effectively. I was expecting to thrown a couple of spades full of sand in there, give it a few shakes, and be left with just the finds. But had to get in there with my hand pushing sand through. Unless the sand scoops a lot more effective than that, I reeckon I'd be better off using your technique and saving my money.