"I need to get a sink waste pipe through a solid 9" wall, I have no core drill
available, what is the best technique?"
[..]

assuming it's a 9" wall with cavity, this is how I do it...

you need a hammer drill, a long 8 or 10mm masonry bit and a piece of the pipe you want
to go through the wall
drill one hole through to the outside, this would be the highest point of the hole you
need, at a slight downward angle.
now use the offcut as a template, place it at the bottom of the drill hole, and draw
around it so you have the circle marked out on either side of the wall
now drill holes around the circle through to the cavity from both sides then chisel the
rest out.

simple (c;

LJ