> Reaction wheels can "saturate" if they compensate for rotation more in one direction than the other on net, so propellant is needed to get them back down.

Torque Rods can be used to desaturate wheels without needing any propellant

https://en.wikipedia.org/wiki/Magnetorquer

This is widely used in smaller satellites operating in Earth orbit.

However, this doesn't mean that TFA isn't BS.