No, you should not use Comet to clean lightbulbs, as the abrasive and harsh chemicals in Comet can damage the glass surface and are not recommended for this purpose. Instead, use a soft, dry cloth to wipe away dust, or a damp cloth if necessary, as a damp cloth is sufficient for cleaning most lightbulbs safely.
I've had to at times give the solder contacts a little sand to improve the contact on some old overhead fan lights we have. So it's not as huge a leap as other "recommendations" I've seen.