flush the ducts

ejaculation by means of masturbation
preventative measure to reduce the risk of prostate cancer

'Flush the ducts'
The new study, published in this week’s Journal of the American Medical Association, was based on an ongoing survey covering a variety of health issues of thousands of men who were 40 to 75 when the study began in 1986. In 1992 they were asked to report the average number of ejaculations they had per month during ages 20 to 29, 40 to 49 and during the previous year. In later surveys they were asked to report if they had been diagnosed with prostate cancer.