The alternative for a sharpening steel?

[Mark Reich]

When I was using the smooth spine of another knife, I was testing whether the edge on my knives was actually abrading or was just rolling over.  I found that even the edge on an annealed 1095 blade could be maintained for a long time with just the spine of another knife.  An actual hardened blade was even longer.  Shocking I know.  But, even the annealed blade didn't wear much, or the polished spine of another knife was actually able to abrade it quite a bit.  

I found the key was light pressure, not even the weight of the knife, and using as few passes as possible.  The first pass on each side was edge trailing, the remainder were edge leading.

Interesting, but why would you use an annealed blade?

It would be significant if you could abrade steel, even annealed steel, on smooth steel. There is no abrasive to make that happen.