It is a particularly nutritious green, but you have to actually eat it to get the nutrients. (And it is a bitter green, so many people won’t like it.) You’re going to get only a small fraction of its nutrients from water in which it was briefly immersed, so really don’t bother drinking the tea unless you like the taste. If you’re going to eat it, I recommend growing it from seed - that way you’ll get proper leafy vegetables that are many times bigger than the stunted specimens you find growing on lawns (which may also be contaminated).
