Well, here in France Christian is considered the "Aikido Prince", and his dojo's waitlist is always full. I've not had a chance to attend one of his seminar as yet. But the way he does it is basically how most of the France's aikido organization does. It is very centralized and not as fragmented as in US. My dojo has no affiliation with Christian's whatsoever but from our Yudanshan who have trained with Christian they say the techniques are the same.
On the subject of effectiveness my Sensei said this technique works very well in an Aikido curriculum, where the attack has a fixed form and people don't really use the free hand. Outside of that I don't know, but I spar regularly with some friends in karate and jujitsu. It's impossible to irimi into their tight inside guard unless you want a hook to the face.
Could you elaborate on how to do that without blocking AND circular movement? Appreciated