Buying High PR: Then Ping?

So I was curious about buying high PR sites to either build a link network, or just to get some of my sites ranking better. I looked into it some and it everyone online says that you lose your PR when you lose the site, because the PR isn't associated with the domain you purchased.

So then the only thing of value with these domains is the fact that you have x amount of back links. As far as I understand it Google deindexes all of the backlinks for an expired domain, so that would equate to the drop in PR.

However! I was curious if you could just buy the high PR domain, let everything get deindexed, and then re-ping all the backlinks to boost your domain back to the good PR? I tried to find some info on this but to no avail.

Another option would be to simply clone the site that used to be on the domain. Would this work?

Thanks!

I would expect that if Google de-indexes all the links, they would add something to their log file so that those links are nulled in value. So re-pinging them would be like flogging a dead horse to move faster.