Wait till you get home, one hour is not going to hurt. It may work quickly, maybe not. There is no way to tell. Believe me, you do not want to be in a car when it hits. You will be tied to the toilet! This is the worst part, good luck.
I ate light the day before just to cut down on the amount I
had to get rid of. You might want to buy some wet wipes. Some
times the rear end can get a little sore from all the trips to the bathroom.
Mix the fleet with ginger ale, as much as you could take in one big gulp. It cuts the salty taste somewhat.(a taste you will remember for a looong time)
Don't take it before you leave work. One hour is a long time and (horrors) if you get caught in traffic you will be in deep doo-doo.(literally)
It starts out a little looser than normal and builds to explosive. You are cleaned out when its nothing but colored water coming out. Drink LOTS of water, apple juice or sports drinks. Do not drink coffee or milk or alcohol. Non caffinated sodas are OK.
Remember that as nasty and uncomfortable as this is, if you have a problem and it goes undiagnosed and untreated the end result is a lot nastier and uncomfortable.