I have bleach dipped my plans for almost 20 years. This is one of the advantages of plants that are attached to wood, rocks or other decor all of which can be removed from the tank.
I use 1 part bleach and 19 parts water. Depending on the plant and the type of large, I dip for as few as 60 seconds and as many as about 135. The thicker the leaf, the longer one can dip. The harder or hardier the algae, the longer the dip should usually be. As examples- I dip anubias for the most time and I do not dip Hygros.
When dipping attached plants, especially those on wood, it is best to try not to dip the wood. Wood absorbs water and thus bleach. It is important to thoroughly rinse plants under water, it need not be dechlored because after the rinse you need to dip the plant in a bucket of water with a strong dose of dechlor.
After this the plant can be returned to the tank immediately.
Note- the algae will not usually not vanish even though it is dead. It will change color and then will vanish over the next few days in the tank. A lot of fish that eat algae may dine on the dead stuff especially the kinds may not eat when the algae is alive. (Think BBA)
One warning re plants that bleaching will kill. These are normally those with thin or fine leaves. A bleach dip will kill them pretty fast. If you are in doubt about a specific plant, do a test dip with a small part of the plant. You can then put it into a small container of dechlored water and see if it dies fairly fast- a number of hours to overnight.
Here is an odd thing I discovered about all the things I use in relation to my tanks. By volume, chlorine bleach is number 1. One of the things I use the least is Dechlor because I have excellent well water from a private well. I only use dechlor when away from home or after bleach dipping some plants. I am able to rinse plants thoroughly under my tap, so I normally don't need dechlor.