The original Siberian Coliu used a "slip ring" as described by Marinov and tested by Kooistra and others, including myself, that was not like a short cylinder but rather was a planar ring.
Most of us have used pure copper vacuum flange gaskets, which are readily available on the internet, and "brush" contacts of liquid metal like mercury or GalInStan. Using this ring, and a triaxial arrangement of armature magnets, ring and brushes, all free to move in rotation with respect to each other, one can then observe and explore the truly interesting and seemingly anomalous behaviour of the system.
That is, when the magnet armature and the ring are both free to rotate, and DC high-current power is supplied to the outer edge of the ring by brushes at opposite points, the "stator" ring will rotate in one direction and the magnet armature will rotate in the opposite direction.
BUT... when the brushes are made to contact the ring on the _inner_ edge, at the same opposite locations, the ring will rotate in one direction and the magnet armature will rotate in the _same_ direction.
The direction of ring and magnet armature rotation depends on the polarity of the DC power applied. The system is set up to "start" with a particular orientation of the magnet armature. When current is applied, the magnet armature will rotate 90 degrees and "lock" into that position wrt the brush locations. The ring moves under power until the magnet armature locks, then it coasts freely, but slowed by the brush contact friction. If the magnet armature is prevented from rotating to the "lock" position, the ring will continue to rotate under power instead of just coasting.
If the DC power is supplied in properly timed pulses, the entire system can be made into a continuously operating motor, with both the "stator" ring and the armature magnets rotating in the _same direction_.
"The easiest person to fool is yourself" -- Richard Feynman