Even if the debt has passed the SOL in your state for suit (variable by state) and even the federal SOL for reporting (roughly 7 years from when the debt discharged) a collector may still pursue you for this money if you owe it. They will just never be able to collect it or report it if you don't allow them to, although they will certainly try and hope you are ignorant enough of the law that they get money from you.
Rapid rescoring is a little-known strategy explained by credit guru Liz Pulliam Weston in her book, "Your Credit Score: Your Money and What's at Stake." Unlike credit repair services, which are almost always a scam, rapid rescoring is a legitimate way to improve your credit score in as little as a few hours – if there are verifiable inaccuracies on your credit report. For rapid rescoring to work, you must have proof that negative items on your credit report are incorrect.
Each time you apply for credit is listed on your credit report as a “hard inquiry” and if you have too many within two years, your credit score will suffer. In general, a consumer with good credit can apply for credit a few times each year before it begins to affect their credit score. If you’re already starting with below-average credit, however, these inquiries may have more of an impact on your score and delay your ultimate goal of watching your credit score climb.