It doesn’t raise fico score
A charge off is one of the worst things that can happen to your credit score and credit report.
Paying off a default account in itself will not remove it and will do very little improve to your FICO score. If you pay or settle the account, at best it will get updated to a Paid R9 charge off status with a $0 balance…..a tiny bit better but still bad.
A much better way to raise fico score is to negotiate a settlement in which you agree to pay all or some of the account in return for the collection agency removing the charged off account from your credit report.
See why-pay-off-debts.html and how-to-pay-off-debt.html for a more detailed explanation.
Just remember to have them send you the terms in writing before you pay them.