Ripley, please don't give (bad) first aid advices if you aren't trained to.
Spin a child fast can damage his spine if done jerkily (remember, you'll probably on the verge of panic at this moment). Or his head can accidentaly smash against something. At the very less, you'll just lose time because it is ineffective. I don't care if this "technique" results into the death of a pet, but this isn't something to mess with a child.
The proper way to try and help a choking person is the Heimilch maneuver. There are 3 variants for adults, kids and babies.
ClickyOh, you can't extract water from lungs without the proper gear and training btw. The only effective way to help a semi-drowned is CPR.