I wasn't able to find any ebook of that book that GodnessInBloom refered "Taoist Bedroom Secrets", but found this one:
https://archive.org/stream/TaoistSex/MantakChia-HealingLoveThroughTheTao-CultivatingFemaleSexualEnergy
In the book it's not refered that massage is especific for breast growth but it says:
"C. Massaging breasts will raise the Organs and Glands’ Chi.
When you massage the breasts or the clitoris, be aware of the Chi energy that is activated as you stimulate the many nerves they contain. The nerves are connected to all the major organs and glands of the body beginning at the top of the crown with the pineal gland. From this point you will begin to feel the stimulation of all the glands and organs as the sensation descends and flows throughout your body Use your mind to guide the glands’ and organs’ Chi to flow to the breasts, blending their energies to produce the best possible glands’ and organs’ Chi. This special blending of organs’ and glands’ Chi can have a very powerful creative and healing effect."
Massage is always refered with an outward movement:
"(1) Place the tongue on the roof of the mouth.
(2) Maintaining constant contact with the skin, very lightly massage your breasts using the second, middle and fourth fingertips of both hands. Moving your right hand clockwise and your left hand counterclockwise, gently press the breasts against the rib cage, proceeding very slowly down to the area of the xyphoid process under the base of the sternum. Bring your awareness there.
(4) Continue to massage your breasts with your fingertips barely touching the skin and gently rotating. Massage them very slowly in an outward, circular motion (right hand clockwise, left hand counterclockwise). Bring your awareness there."
Activating glands
https://archive.org/stream/TaoistSex/MantakChia-HealingLoveThroughTheTao-CultivatingFemaleSexualEnergy
In the book it's not refered that massage is especific for breast growth but it says:
"C. Massaging breasts will raise the Organs and Glands’ Chi.
When you massage the breasts or the clitoris, be aware of the Chi energy that is activated as you stimulate the many nerves they contain. The nerves are connected to all the major organs and glands of the body beginning at the top of the crown with the pineal gland. From this point you will begin to feel the stimulation of all the glands and organs as the sensation descends and flows throughout your body Use your mind to guide the glands’ and organs’ Chi to flow to the breasts, blending their energies to produce the best possible glands’ and organs’ Chi. This special blending of organs’ and glands’ Chi can have a very powerful creative and healing effect."
Massage is always refered with an outward movement:
"(1) Place the tongue on the roof of the mouth.
(2) Maintaining constant contact with the skin, very lightly massage your breasts using the second, middle and fourth fingertips of both hands. Moving your right hand clockwise and your left hand counterclockwise, gently press the breasts against the rib cage, proceeding very slowly down to the area of the xyphoid process under the base of the sternum. Bring your awareness there.
(4) Continue to massage your breasts with your fingertips barely touching the skin and gently rotating. Massage them very slowly in an outward, circular motion (right hand clockwise, left hand counterclockwise). Bring your awareness there."
Activating glands