In dock, out nettle.

The paired plants recall a charm for a nettle sting: dock is welcomed in while the nettle’s painful effect is urged away. The words express a wish for relief, not a claim that dock is an effective treatment.

Figuratively, the brisk movement between “in” and “out” points to someone who keeps reversing course. The saying draws attention to wavering or inconsistent conduct rather than a settled position.

Use the proverb as a pointed comment on someone who repeatedly changes a decision or position. It emphasizes the back-and-forth itself, without explaining the person’s reasons.