Message In A Bottle

I had this idea for a while but no motivation/was too busy with university to give it a go. Earlier I was discussing the Blender tutorial with a friend who urged me to finish them; I didn't quite do that, but I thought I'd test out the concept for this at least and get a few basic ideas of what may or may not be possible. 
I tried out a few different ideas to add the words in the walls of the bottle and this seemed to work best. It's just that I still have issues with transparency and the messing with the properties. The roundness/thickness of the glass doesn't show, which is annoying; I figured the issue was in the 'depth' but it got too frustrating and this is basically the best I could do and it doesn't look so bad anyway.