If getting your hands on one is really difficult and you don't want to shell out extra money for a training gun, then make a mock-up yourself.
The dimensions are usually available online, then get an old floor plank, or glue some cardboard together and cut to roughly fit that size.
A bit trickier with revolvers but doable.
When the right to effective self-defence is denied, that right to self-defence which remains is essentially symbolic.
Freedom: Please enjoy responsibly.
Any idea that relies on murder for its survival in intrinsically weak.