Lubrication = No
This masturbation method simply involves the use of a drinking glass to stimulate the testicles and the perineum area as well as the anus (if desired).
(1) Sit on the very edge of a bed and let the testicles hang over the edge of the bed.
(2) Use a simple and quick up and down jerking method to while holding the glass against the area underneath the testicles just so they dangle onto the edge of the glass.
(3) It is possible to use the glass to put pressure on the perineum. This adds a very unique sensation to the masturbation session.
NOTE: As a variation, you can lean back on the bed a little and use the glass (or other object) to put pressure further back in the area of the rectum/anus.