Hi webman, hi folks.

Click in sequence on the scenes tabs of this SU file for ideas:

Steps with comments.skp

@webman said:

Hi, thanks for replying. I tested your suspicion...

It was no suspicion. Peter has it covered nicely.

I expect you're getting something like this?
cuts4.png

Which, if you don't stop the Push/Pull at the opposite face, it will continue extruding. The correct use of Push/Pull would be to either click on the opposite face to stop the extrusion or, if you know the thickness of the wall, start the extrusion in the right direction, let go of the mouse and type that distance followed by the Enter key.

Thank you Peter for the nice words and for posting the videos.