I didn't do perineal massage during PG. My midwives did some hot compresses and oil during pushing. I had a third-degree tear, but it was almost certainly due to DD's position and the fact that I pushed her out relatively forcefully, so that my perineum didn't have enough time to stretch well.
I had an extremely strong pushing urge that I found impossible to "breathe through." As well, the midwives were unable to get her heart tones at the very end of pushing, so they were encouraging me to push. It still took a LOT of pushes between crowning and her head coming out. DD's APGARs were 6 and 8, and she cried a lot after the birth, so I think she was certainly stressed. Position-wise, her head was not fully flexed, and after her head was born her body did not turn (restitute) as it was supposed to, so I had to push both her shoulders out at once. Her cord was wrapped around her body strangely, which we think might have been the reason she didn't turn. Anyway, my perineum tore a bit when her head came out, and then when I birthed her shoulders, it tore more and I also got some side vaginal tears as well. My midwives said they had never seen a tear like mine (a very dubious distinction). We transported to the hospital for stitches as they felt it was outside their expertise. The OB who stitched me up agreed that it was probably the position and timing as much as anything, and that an episiotomy would have made for a worse tear. My only regret is that I didn't try to turn from a hands-and-knees position to a squat after her head was out -- I've often wondered if that would have helped her to turn.