I use that green Listerine stuff that feels like it's burning your mouth. I love it, but after i've spit it out it always leaves a weird, not overly pleasant residue in my mouth, so I then wash it out a couple of times with water.

But I always think that by doing this it defeats the object of using the mouthwash in the first place. So, does rinsing with water 'dilute' or negate the effects of the mouthwash, or has the mouthwash already done its job by the time you've swilled it around and spit it out?

Hmmm, interesting...