Wetutt seems to refer to the initial pounding while taawaa is used to describe finer grinding (BTD translates wetutt as "pounds acorns" and taawaa as "grinds acorns"). However, wetutt may also be used for the whole process, as Mesa Grande dictionary defines as, "pounds acorns, grinds acorns".
Can also refer to "large mortar" (Mesa Grande)