I was trying in vain to jailbreak my iPad and iPhone using Absinthe but getting nowhere as Absinthe kept closing itself as quick as I was double clicking it. I found a solution and thought I'd share it.
1, double click on your downloaded copy of Absinthe.
2, drag the Absinthe app to your desktop and drop it there.
3, right click and Show Package Contents.
4, Open Contents/MacOS and run Absinthe-10.6 with Terminal.
Absinthe should then run normally and you can jailbreak to your hearts content