On May 22, 12:45*pm, MM wrote:

But a mitre box doesn't have any guide 'clip' to stop the saw wobbling
in the groove. The clip was the JointMaster's secret weapon.

First of all, learn to hold the saw flat against the guide.

Secondly, a decent and new mitre box doesn't rattle around the saw.
Better mitre boxes even have adjustable guides at the top, which you
can adjust down to blade thickness, not just kerf width.