Maybe they can find out what empties the bucket.

E.g. meditation, yoga, ...

It's definitely bucket-like for me, and I can attest meditation empties it. Whenever I stop meditating, mental busyness and subconscious anxiety slowly build up. Half hour a day is enough to keep it away. I just keep bringing my attention back to the breath, trying to feel into the physiological need to breathe (which is usually occluded or distorted by mental activity). Whenever I feel I am actively holding to some tension, I allow myself to release it. That's all in terms of instructions, and for me it works wonders. I look at it as the equivalent of flossing for the brain ;)