shaman,
Brass is different than lead. Annealing a case neck and then allowing it to air-cool works fine.
The old advice about standing cases neck-up in water was mainly prevent the case-heads from being annealed, because the advice usually involved heating the necks "red hot," which is far more than needed, and in fact tends to make them too soft. The final part of the sequence was tipping the cases over into the water, supposedly to finish the annealing process. But it's not necessary. You can just let the cases stand in the water until they cool.
The big deal is to avoid heating the case heads enough to anneal them.
