Therapeutic Effects of Masturbation

I've read in an article on religious views on masturbation that there were individuals in the Buddha's time that viewed masturbation as therapeutic. The reference given was (Vin. III 109) which I'm guessing stands for a part of the Vinaya, but I cannot really navigate my way and find the source. I'm wondering if anyone knows about these arguments for masturbation, and those which the Buddha gave in disagreement to these views. Ultimately I'd like to know whether masturbation is always a fetter, if one gains many benefits from its non-practice. Thanks.