Safari 6: Open and close tabs with middle click?

On Lion I installed an extension which game me the ability to use middle click to open and close tabs, and I used Better Touch Tool (BTT) to use a 3 finger tap to act as a middle click.

Since using Mountain Lion DP4, and subsequently the final release with Safari 6, I am only able to open tabs with a middle click, and I have to use keyboard shortcuts or by clicking on the tab close X.

Is there anything which will give me middle click to close a tab which works on Safari 6 under Mountain Lion available now?

I've set up the same 3 finger middle click gesture in BTT and it works great with Glims for Safari's middle click to close setting.