but the point of my question was precisely that in 2012,
the way that Google is presented within Safari is different
(e.g., there is now just a single search bar),
so some of the info on the old threads is no longer relevant.
That is why I titled the qustion clearly "SAFARI 6".
However, I have discovered the answer myself.
I think I was being just too impatient.
The same option of CLEAR RECENT SEARCHES does come up
if you click and hold on the magnifying glass icon to the left of what is now the single Google search bar.
This click and hold opens a roll-down menu, and near the bottom is the CLEAR RECENT SEARCHES option.