Just ordering Scotch wouldn't work for me: I love the stuff and, corrected for the alcohol content, I will consume it faster than beer. If you have the same 'problem', what may work is ordering water on the side.
I have/used to have this problem - which is why I gave up drinking. In fact as I read this, I thought to myself "yeah, that's fine if you have the will-power not drink the scotch very quickly and order 2 more in the course of your friends single bottle of beer.
I find spirits much easier to drink in rapid quantities without realising I'm doing it. Quite apart from the lower volume, the lack of carbonation makes the onset of drunkenness less evident
