You are correct. There are many products and techniques available. Some work great and some don't work at all. The various over the counter products give the least predictable results. To get a really great result you should probably use one of the products sold through dental offices which utilize custom made trays for home application of a bleaching gel. There are several great ones out there. Our favorite is Nite White® Excel. Besides giving a great result, this product has overcome the sensitivity problem seen with some of the other products.