In a recent video released by Matt Cutts, Google’s head of search spam, Matt answered the question, “How can a site recover from a period of spamming links?”
The example given was when Interflora was penalized by Google for buying links and only was penalized for 11 days. The question was, how can a site with a penalty get their rankings back in 11-days like Interflora?
Matt didn’t give a specific answer to the question, instead he said he wanted to answer it in a general sense.
Matt said that you should disavow the bad links with a vengeance and disavow all the links that might be paid. Don’t use the disavow tool a single link at a time, instead use the domain level disavow option. Matt said this before, explaining that you should use the disavow tool more like a machete.
So, if you know you paid for links between a specific date range, technically, you can disavow all the links you acquired between those date ranges, or at least disavow most of them, at the domain level.
Here is the video: