to do a water-spell,
there are several ways,
one is to make a paper-spell and flush it down the toilet or a river.
Another is to make a potion with a cauldron, to mix up a bunch of herbs and things with elements to get the desired effects.
Potions are used by herbalists even today.
I like to make loose-packed forest-fruit tea, it is an elixer of life, cures cancer increases longevity.
I say loose-packed since then you know what you're getting, and paper really interferes with flavour.