I’d answer: it can do both, and the difference is whether we keep checking. In the early suttas, the Buddha’s not-self point is not mainly a theory to be proved; it is a seeing of how “mine” arises around the aggregates. When the label sits for one breath, the grip may soften because attention is no longer adding a report. It can also become more polite if we are still waiting for a sign that the looseness is “enough.”
That is why I like the next ordinary sound. It is not a test; it is simply what is there. If the label appears again, we can note it again, without making the note a manager. In the Anattalakkhaṇa Sutta, the Buddha points to unsatisfactoriness in clinging to impermanent phenomena, and in MN 28 to the habit of treating the aggregates as owned.
So my short answer: the one-breath pause helps only while it stays a contact, not a seal. If it starts feeling like proof, shrink it.