If it's a throttle body spacer then to install it, you remove the TB, attach the spacer, then bolt the TB onto the spacer. A spacer is just that: a device that moves the TB physically further away from the intake plenum. They're about an inch thick, more or less.
A helix or tornado device is only about as thick as a piece of tin gasket with little fingers sticking into the airstream. It really isn't a spacer per se, it's a turbulence producer.
Unless someone has found a way to invert years of science and several tests of devices like turbulence producers, it is generally accepted that a smooth airflow is the most efficient means of getting the air from one point to the next. The deposits that build up on a valve can cause unwanted turbulence that slows the speedy filling of the combustion chamber. I would imagine that any other turbulence, whether it's introduced by build-up or a tornado device, would do something similar.
But I'm no engineer, either. In the past I've given careful consideration to things and thought I had arrived at the correct answer, only to be proven wrong. There's no dishonor in admitting I was wrong. Many intelligent people (you see how I'm trying to get you think I might be among them? Neat trick, eh?) have used erroneous conclusions to finally get back on the track to finding the truth. The Earth used to be flat and ride on the back of a tortoise, too.
I stand before you heavily enlightened by all my past mistakes. And I'm sure I'll make more! At least I'm not sitting like a bump on a log, and neither are you. Keep experimenting. And if this tornado thing actually yields better mileage and/or power you just might have stumbled onto something. Lots of discoveries were just that: discoveries of what was already there while looking for something else. Just keep your eyes open as you do your testing to be sure you're eliminating as many variables as possible, or at least able to explain them.