I have used Zicam in the past, but they taste AWFUL. They do work though.
A couple of weeks before Christmas, I was starting with a cold, and bought Airborne tablets. You put them in water and they fizz (like Alka-Seltzer). You drink this every three hours, which I did for two or three days. I did not get a full-blown cold, and only had to deal with a runny nose.
I prefer the Airborne...it tastes better (no after taste either).
ETA: I never took either throughout the night. In fact, I think Airborne is every three hours, but not to exceed three times a day.