Sgt_Kickaxe - 7:19 pm on Sep 24, 2012 (gmt 0)
Some things we know:
- Google has made clear they don't want webmasters sculpting pagerank.
- Google doesn't follow links, they visit pages directly.
For those two reasons I don't think the suggestion in the O.P. would work. Google wouldn't want it to nor would they ever directly follow a link so blocking the road between site A and site B would not help.