I have used light sugar syrup in a pump bottle with some success. You turn it to the finest mist and spray the entrance area first, including the bees. Very quickly, the bees will be focused on licking up the syrup and getting it off of each other. Then you gently open the top cover and mist all the bees on top of the frames. Again, they get to licking each other, and stay pretty calm.
In my opinion, it will not slow down a hot hive, but if you have pretty calm bees, it does work. But it is not as effective as a smoker. With a smoker, I can drive the bees down before putting a super on or whatever, whereas they don't run from the sugar spray, they just lick everything like crazy. Might be worth trying, if you are in a hot, dry location. Bringing a small extinguisher might be a good idea, too!