The description for the Boots of Speed states:
While you wear these boots, you can use a bonus action and click the boots' heels together. If you do, the boots double your walking speed, and any creature that makes an opportunity attack against you has disadvantage on the attack roll. If you click your heels together again, you end the effect.
Obviously, activating the effect requires the use of your bonus action. However, just clicking my heels together should in general have no action economy cost and the sentence describing how to end the effect makes no mention of using your bonus action.
So can I end the effect of Boots of Speed by clicking my heels together without using my bonus action?