spot dosing with a syringe also works well as I have done this, followed by continually overdosing the excel.
I have used the same method in the past but instead of removing the plants, I sprayed them during a water change when they were out of the water. It is much easier to do it during a water change than it is to uproot and replant. Works equally well for BBA on hardscape, equipment, or the tank glass as long as it is out of the water during the water changeHe took his plants out of the tank and sprayed them down using a spray bottle filled with Excel. He eradicated a huge amount of BBA with 1 quick treatment in only a week! Just take them out, spray them down, and put them back in! A quick dip would also be equally effective, but maybe not as practical for all situations.
In his experience, this method completely cleaned a huge Java Fern on driftwood with 1 shot in just about a week!