Sounds scary as hell whatever it is. I don't want one.
No, not scary. I found it fun; but then I can be strange.
It is just a rapid descent, with the goal to maximize vertical and/or lateral separation.
Do this with a CFI, and discuss when to use the techniques. I was taught two approaches:
1. Push nose over, like the OP did, and accelerate to Vne. If you want to maximize lateral distance, keep some power in. If you want to maximize vertical distance, power to idle.
2. Bank, push over and power to idle, I was taught up to 45 degrees. Once bank is established, pull back to tighten the turn, add rudder to push nose down and slip to add more drag until approach Vne. Wings level, then nose up to come out.
Again discuss with a CFI and know when to use them before you attempt it. The second one is definitely an aggressive maneuver, but is useful if you need to change direction and/or get vertical separation. Note: it does not provide lateral separation. As such it really is rather limited in usage.
I originally asked the question because the OP said he went 60 degrees. No statement on direction (pitch/roll); which started this tangent.
Tim