zap's method works a treat, that is the method that i tend to use when creating glass materials using the a&d shader, i'm just rendering a couple of examples of a standard wine glass model using zap's technique for colouring the glass, will post them when they are complete.
my machine is rubbishly slow and not very high spec, plus i'm at work so should be doing work
they won't be too long tho and hopefully you will be able to see how nice the glass can look when using these techniques.
the next step for extra realism would be for my to incorporate some hdri into my scene, the scene i have used is just lit with two sky portals as area lights with the opiton to make them visible turned on