Thanks all for the great ideas -- I really like the idea of the PVC pipe, I may end up going with that.
I'm pretty good at pouring, but with one or two glazes that REALLY show overlap, I just never seem to be able to get the perfectly even coverage I get with dipping. Same with dipping in a shallow tray (which I mostly use for plates).
Neil, I've been able to use some glaze / form features to hide glaze lines, but sometimes what I want to do just doesn't make it possible. I think the PVC pipe is kinda exactly what I'm looking for.