To show just how much contradictory information there is on this, I have read on the German sites and forums not to strop after a shave at all - here's the reason why.

After the shave, the microscpoic edge is effectively bent and twisted from slicing through all our hairs. Stropping straight away has a huge risk of bending them back again, thus over time stressing the metal at the point of the bend, at best, and at worse snapping them off into the hone itself, which needless to say is very bad.

Over 24-48 hours the edge relaxes, and things are more or less aligned again, and you can strop - the main purpose of which is to finely align the edge of the blade so that its all pointing in the right direction.

I am the first to admit I am a total noob at all of this, but to me the above makes perfect sense with my very basic knowledge of metal.