My sparge arm tubing fits snugly inside the hose. I found that 2 hoseclips are necessary, but don't over-tighten then.
If you find a more over-engineered/shiny/expensive alternative I'd be very interested
Loving it -> These are both some great ideas, I've been thinking along the lines of going std 1/2" myself and a couple of weeks ago I found one of these taps on ebay where the hoselock fittings pop straight on the end of the tap (although its not heat resistant) works out about the same costs though.