Found this at Mitre10. Cost $17 and makes an ideal tool for the job with the addition of a length of 15mm hose(8mm inside diam). Has plenty of suck and blow, being designed for clearing blocked drains. Weighs nothing, 400mm long o/a and 50mm diameter.
I retained the small
drain rubber, which has an internal thread. Makes emptying your gold or whatever easier. Lots of options for a d.i.y. er