I'm pretty new here and not the expert, but I'd say it won't show "instantly" .
For example, on my FreeCreditReport.com credit analyzer, it said I needed to open a major credit card to boost my score. You see, about two years ago my wife and I PAID OFF our cards and closed the accounts. We thought we were doing the right thing at the time (besides, I always pay for things with my debit card which can double as a credit card..!).
Long story short, I did what FCR.com said and opened a "share-secured" VISA card. It took until the first statement was generated by the credit union for that card to appear on the credit report. But when it did the score went up by 20 points.
I'd bet on it taking at least 15 days to 1 month to show. Plus, I'd be on the phone to those creditors (and/or send letters) requesting them to update their reporting to the big three bureaus ASAP.
Good luck!
FICOnater2007