Thanks to all for your answear and advices.

Of course you're right, Dougwalkabout. The "mk5 push dagger" is just an idea, an option... In a case of self defense, surprise may be a "+", and there is no surprise with a stick. And no problem to me quit a stick in the hand of an "average women" for an exemple. And almost no risk.

To quit a push dagger in the same hands is more difficult...

But as I said it's just an idea ...