Throttle body spacer

Okay, I'm pretty new at this but I'm seeing throttle body spacer with claims of adding 20 horsepower and I find that pretty hard to believe. This has gott to be B/S! Can someone let me know if adding a throttle body spacer will make any kind of difference at all.

total bs...

Those spacers claim to do a "vortex" action that mix better the air and fuel, and add some more space in the intake manifold.

Totally BS.

It will add a funny sound when you slightly press the gas pedal.