The thinking mind is useful, we need it. But when the thinking mind has done it's job for us it is nice to switch it off!

It is common in many cultures to drink alcohol as a way of switching off the mind, in other cultures smoking is used.
Watching TV, eating, reading, listening to music are all ways we have of 'not stopping thinking' but actually distracting ourselves from what we are thinking about.

When you do several rounds of Kapalbhatti you will oxygenate the blood and therefore the brain.
This has a profound influence on the mind because the blood supply to the brain improves and the brain relaxes.

Can I prove this? No!

So you will have to try it and see if it works . . . .

Try this:
3-5 rounds of Kapalbhatti pumping - 30 to 100 pumps, no breath retention.
10-20 rounds of deep Yogic breathing - exhaling twice the time of the inhale.
10 - 20 rounds of alternate nostril breathing using a 2-8-4 ratio. Working from 4-16-8 - and going up into longer breaths and longer retentions - focus the mind and breathe deeper and longer.
Sitting for 15 minutes in meditation.

Try it, it shouldn't take too long.