"Massage Therapists advise to drink water after a massage, but there are a lot of reasons for this - way more than simply 'flushing toxins'."
Anyone who has had a massage has probably heard "After your massage, drink water to flush out the toxins that got stirred up during the massage". Well, this is only very slightly true. While massage can help flush the body of toxins, it can't generate so many toxins that your body is basically poisoned if you don't drink enough to flush them out (that's what your kidneys are for). So why the water? Lots of reasons. Your body basically needs it, and we usually in general don't drink enough of it and this can affect your skin, organs, muscles, and more. It hydrates and heals the muscles that the massage just manipulated and moved around, plus it helps all the fluids that the massage got moving through those muscles to keep moving and get where they need to go.
This is only a very brief summary of why we recommend people drink water after a massage. I have a much more detailed explanation here: Why Do Massage Therapists Tell You To Drink Water After Your Massage?