Pretty much any whitening product will work. The crest whitestrips are sold in dental offices too so that must mean it has to work. If you are not sure talk to your dentist about what would be best for you.
If you want to use an over the counter system I've found the best thing to use is the Listerine pre-rinse mouthwash. It tastes much better than the Colgate. Otherwise you can go to the dentist for help.
