Negative accounts stay on for 7 years after date of first delinquency; paying does not reset that date.
Since you've got credit cards that are charged off, that means they have balances, and those balances continue to affect your utilization.
For an example, I paid a small charged-off credit card last fall. It wasn't enough $ to significantly affect my overall utilization, but when it updated, my FICO score went up 20 points. Victory was short-lived, though, because when I pointed out to them that it was reporting wrong, they changed it to be more wrong, and my FICO score dropped by 23 points. My utilization was 52%, 53%, and 54% on those three reports, fwiw. So paying the chargeoff didn't drop my overall utilization one bit, but the 20 points was from not having that delinquent balance.
You might also try seeing what the FICO Score Simulator (available for TransUnion and Equifax reports only) says will happen when you pay down delinquent balances. The score simulator was quite accurate at gauging the effect of paying down my chargeoff.
As a comment on re-aging, there's two forms:
1) For an open credit card, an agreement between the cardholder and the creditor to "start over," which would remove prior delinquencies. There are specific guidelines for this from the FDIC and each lender has to set policies about requirements for this sort of program.
If you want to read up on that: http://www.fdic.gov/regulations/laws/rules/5000-1000.html
2) There's also a form of re-aging that's not permissible, which would involve changing the date of first delinquency to make a delinquency appear more current. This sometimes happens when a charged-off debt is sold, because a fresher account is worth more money.
On Experian only, the date of first delinquency isn't reported, so the date of status is used, however the date of status isn't supposed to be reset when payment is made, I believe. I know there's been a huge flap, but I haven't been keeping up with what's happened on this.