Onion rings. I've tried with beer batter and the batter falls off. What is the perfect recipe?

I use a very old standby recipe. Soak onion slices in ice cubes and milk (any kind will do) for at least 1 hour. Drain dredge in flour. I use plastic bag and shake the sliced in batches. Drop in hot canola oil until lightly browned and crisp, drain on paper towels, sprinkle with salt and yummmmm. Light, crisp and crunchy. A family favorite for over 45 years.

The few times a year I make onion rings is with a tempura batter.

You might first try dredging the onion rings in flour before coating in the beer batter. The flour may help the batter cling in a manner that is similar to other methods (for example -- flour dredge, followed by egg dip, followed by breadcrumb dredge).

I came across this recipe and have wanted to try it but haven't yet. The reviews are pretty convincing and if you try it, please let me know how it goes.
Lisa
http://foodwishes.blogspot.com/2010/05/can-i-get-onion-rings-instead-of-fries.html