Ooo, douching is BAD. Do NOT do it unless you're specifically instructed to do so by your physician (and it's very rare for a physician to have you douche).
Douching definately does encourage infection. See, the thing is that the vagina is a self cleaning bit of you. And inside it you have a very delicate balance. Douching interrupts that balance and washes away the good stuff that keeps your vagina healthy - which makes it that much easier for the bad bacteria to overwhelm things and cause infection.
Honestly, there's no reason to douche. Your vagina cleans itself. And the way it smells is the way it is supposed to smell (unless you have an infection - in which case you need to treat the infection by seeing your doctor and getting appropriate treatment for whatever infection it is rather than making it worse by douching). It's not supposed to smell like "ocean breeze" or "springtime fresh" or even like nothing at all. It should smell like a vagina.
So while these treatments are supposedly going to make you smell better or make you cleaner, they're actually really bad for you and can cause/encourage infection. Honestly, if I had my way, such things and their incideous commercials would not be avaliable - because they're unnecessary and harmful.
If you use the board search function and look for "douche" you'll find other information about it.
Scarleteen Sexpert (and Labia Lady)