I'd be very careful with this! Do you really want to be simulating giving birth over and over? What might this do to your pelviv floor?

This is my opinion about devices such as the epi-no. *hops up on soap box*

To me it is telling womin that their bodies are no good at preparing to birth their babies and they need outside help. To me this device implies that a womuns body is inadequate and may reduce a womuns confidence in her body to birth without assistance.

I do recall reading an article about this device and its potential to cause damage to the pelvis floor. I must find it and provide a link.

If you really want to try something to reduce the chances of tearing could I suggest some gentle perineal massage? Once again, don't over do this as it can cause tenderness and swelling of the tissues and so when it comes time to give birth, the tissues may not stretch as well.