I need to route a 3" PVC drain pipe from my garage (from the washer) to the
kitchen drain.

There is an interior wall separating the kictchen and garage. The washer is
sitting against this interior wall about six feet from the exterior block
wall. The kitchen sink is against the block wall on the other side about
another 4 feet from the interior wall. So from the washer to the kitchen
sink you have to route the drain along the interior wall, then make a turn
to connect to the kitchen drain.

My question is, should I do the routing from the inside or outside?

Inside: Run the drain from the washer inside the interior wall. When we
reach the exterior wall, make a 90 degree turn and go through the interior
wall. The other side is the kitchen cabinet. Drill through the kitchen
cabinet divider and reach the sink bottom, then open up the wall from the
inside, and connect to it.

Outside: Run the drain from the washer inside the interior wall. When we
reach the exterior wall, drill a hole in the concrete block wall so the pipe
can run through. Next locate where the kitchen drain is in that wall, knock
it open. Once you see where it is, break the exterior wall from the outside
and notch a trench that will take you from there to the kitchen drain.
Connect the pipes up inside the block wall, then cover it back up with
concrete, apply stucco and repaint the outside.

Which way is better? How do one drill a three inch diameter hole through a
conrete block wall? How easy is it to chisel out a trench along the wall to
seat a 3" pipe completely inside? I think that would be a lot of work? I
think routing the pipe completely out and back in will be real bad right?

O