If you remove the plants, you can manually remove what you can and also use a spray bottle filled it with H202 and give the plant a good spritz before returning to the tank.
You can also use a syringe and target spray problem areas inside the tank with the peroxide.
Some use Flourish Excell instead, but I'm not a fan of this product.
It's important to limit the total amount of hydrogen peroxide you add to the water collumn.
My rule is 2mm of H202 per gallon per day of treatment.