The ultrasonic water blaster can be rough. Skipped going to the Dentist for about 4 years quite a while back. She hit me with the water tool. Then she stopped for a minute and exclaimed "Oh look!" I said "what?" and she stuck her finger in my mouth and retrieved a very small black hard as rock nugget. Showed it to me on the end of her finger. I told her "you have absolutely no idea how long I've been looking for that!"
She punched me in the arm and kept on with the blasting.
