Unfortunately, most of the material components you would need to counteract the waters of Lethe are either rare or nonexistent outside of the celestial planes... but thinking about the way the water works does give you another idea. It's not the easiest, but it might be your only option...<br/><br/>Potentially, you could bolster the dryads' resistances to the water by combining divine and arcane magics in a ritual... but it would be taxing. It would take probably two days worth of magics from both parties involved, meaning you would essentially be defenseless for 24 hours after completion.