According to the evaluation I got with my credit score: "There is no "quick fix" to improve the score if the serious delinquency indicated on your credit bureau report is valid. However, as these items age and fall off the credit bureau report (most late payments stay on your report for no more than seven years), their impact on the score will gradually decrease."
I have a charge-off on my account and my score sucked. I think I was in the 4th percentile, and everytime I applied for credit, I was denied! I could NOT get any credit at all, not even secured ones! But when I asked 3 people to add me to their credit card accounts (a few years after my charge off) my credit score improved. It is now 637 (23rd percentile) with Equifax.
One thing that I think was helping me is the fact that my charge off was sold to another creditor, and the balance was aritificially showing up as $0 on Equifax, and "unkown" on Experian. I dont know how the score is calculated, but I just assumed that if I can make the balances $0 for real, it will be good for my credit score.
Basically, even though chargeoff suck, they are not the end of the world!
Over the past month, I made some changes: I removed myself from 3 of the accounts that I asked to be put on; I opened 3 credit card accounts in my own name; I took out a secured loan; and I paid off the charge-off. I'm just waiting to seem my credit score plunge! But I'm sure it will start to get better as the dust settles.