I have been using TePe pink for years after being recommended to try them by my dentist. My teeth are crowded and it is difficult to clean between them. TePe's certainly help, and in conjunction with floss picks do a great job in keeping plaque down and gums healthy. I notice a difference within a day or so if I don't use TePe and floss.
Do make sure you buy the right size though - as a small TePe wont be as effective if you have reasonable size gaps between your teeth. Ask your dentist which size s/he recommends, s/he will probably be able to give you a good estimate.
Overall a good product and a pack lasts me a few months.