Robert_Charlton - 8:13 am on Jan 26, 2013 (gmt 0)
In my post above, I twisted one of my main points around like a pretzel....
...since it's likely that your old index page is tainted too, you couldn't selectively 301 untainted pages.
I meant to say that in this situation you can't simply redirect the entire domain with a 301... you'd need to select untainted pages. Sand said it right.
Following up on other questions...
When we are talking over 50,000+ backlinks in Google, it's also very difficult to label which ones you think are bad links. Google doesn't tell you which links are bad, so therefore, making assumptions leaves room for error.
This is why I suggested disavowing many more than necessary. You're not worried about preserving link juice, and you could disavow entire domains, which might cut into the 50,000 very quickly.
If you are going to do any redirects from the old site at all, it's likely that the links which send the old site good traffic (if there are any) would turn out to be good links, and those are the links you should consider redirecting rather than disavowing... but redirect them only after the disavow request is accepted. You're right... don't consider redirecting pages on a partially penalized domain... not when the penalty is for spammy backlinks.
It's worth noting, btw, that in mid-November this thread discussed that disavowing 100% of the inbound links to a site apparently isn't an acceptable approach....
My Google Disavow Story
I'd stay away from using these here. Either might be seen as the kind of "sneaky redirect" that Google warns against in its quality guidelines.
For a resolution, I did receive a recommendation of noindexing the entire site and adding links to related content with rel='nofollow'. Basically, a message tells the customer we have re-branded allowing them the option to go to the corresponding page. Since we can't force the 301s, this seems to make the most sense.
The idea hit me as well, that it might not be bad to have visitors pause at the old site to get the news of rebranding. Though the approach does comply with the "letter of the law", and there are no sneaky redirects, something about the approach gives me pause. In my gut, I feel that Google wants best efforts made to clean up the old links first, and somehow that's going to override everything else. This is just a gut feeling... no strict logic to it. I'm curious whether anyone has successfully done it this way.