This never works.
In some ways, incest is like post-traumatic stress syndrome, a broken bone, or a bacterial infection. These injuries are extremely curable, but only if you get professional help.
For anyone healing from incest, forgiving your abuser is the very, very last step. Many survivors have been abused so badly that they never forgive their abuser, and yet feel healed from the effects of incest. And this is perfectly fine.
If you are in the beginning or middle stages of healing from incest or child sexual abuse, don't even think about or worry about forgiveness. Make sure you are working with a qualified professional, and concentrate your energies on yourself. Focus on healing yourself. At the very end of your healing journey, you can work with your therapist on the subject of forgiving your abuser, and you can decide at that time if it is something you choose to do.
Until then, don't waste your time or energy on it.