While I can understand that some may be turned off by the practice, or it may lead some to associate the practice with homosexuality, us heterosexuals can find prostate massage a major source of pleasure.
Here's a description from an asian site:
Male Sacred Spot Massage & Prostate Therapy
The internal G-Spot massage is made by inserting a well lubricated finger into your anus. The masseuse will gradually increase the finger pressure, until firm, expand the massage to the surrounding muscles on both sides, changing hands and position as necessary.
These muscles, which may be sore and hard at first, will release and soften dramatically with continued massage. You may, yell and scream a lot; that's fine, for it helps to release stuck emotions. You will be surprised at how great you feel as you release these areas.
Prostate massage feels better when you are somewhat erect and excited, and it can produce a very thrilling ejaculation if it's done during lingam(penis) massage (even this loss of energy is not encouraged).
A single massage can produce dramatic progress, freeing the gland and surrounding tissues, increasing the flow of blood and energy to the prostate, and releasing the energy that has been trapped in this sensitive area. This newfound physical openness allows more blood and oxygen to the area, creating healing and general softness of the prostate.
It will also enhance your lovemaking. The area of the male g-spot, and the prostate gland are known Tantricly, to be the energetic access point for the Kundalini energy which leads to enlightenment. A gentle digital technique is used for contacting these subtle places with increased receptivity. Expert stimulation, eye contact, and conscious focus are used to heal trauma or clear any old or negative imprinting.