I'm currently treating my entire tank for BBA (due to my CO2 running out while I was away) using an overdose of Excel (2x recommended dose) and it seems to be working pretty well. All the BBA in the tank is now reddish pink in color and hopefully it will start to completely die and fall off of leaves and driftwood and equipment that it is attached to.
I've found that H2O2 appears to work great, but you must be persistent. Every time I have tried to treat with H2O2, it has turned red for a few days but then come right back within a week or so. Perhaps if you've fixed the underlying problem causing the BBA H2O2 might work. I can't say for certain that I had fixed the underlying issue when I used H2O2 which might be the reason it came right back. That's just my experience. Good luck!