The effectiveness of this technique is the repetition of the movement and the force in two opposite directions on the muscle and fascia.
Do not perform this quickly if anything slower is better , follow the recoil and elasticity of the tissues.
As always I am a huge fan of the PARASYMPATHETIC nervous system and I think your client will really relax and allow healing to take place once they feel that you are working with them and not forcing the tissue to soften.
If anyone is interested in reading a good book ( JOBS BODY Dean Juhan) is a book that had a big influence on the way I massage. I remember one of his most impactful lines ” you cannot bully the body ” He has a very interesting take on massage and the effect it has on the body.