The double chin — submental fat — is one of the most-searched aesthetic concerns, and two very different treatments target it: Kybella, an injectable, and CoolSculpting, a device-based cooling treatment. Patients comparing them are really asking which fits their situation, and for an owner the comparison spans both the clinical (different mechanisms, different patients) and the practical (one needs a device, one doesn't). The right answer is patient-specific, not a default to whichever you happen to offer.
This is general education for owners, not medical advice. Treatment selection is a clinical decision for trained providers.