Ok the way that article was written was really funny. I must admit that this sounds gross but I know that ejaculation prevents carcinogens building up in the gland. The prostate, together with the seminal vesicles secretes the bulk of the fluid in semen, which is rich in substances such as potassium, zinc, and few other things. I guess the more you flush the out the less there is to hang around and damage the cells that line them up!