Looking at the site, the word is "totally mechanical". In their mind having a switch that makes a contact when you press it is "totally mechanical" and requires no wires.
It would be a great idea if you really like running full power through a switch connection that you mechanical break, which is never the best idea, as it will cause arcing ect. However that sort of switch is best left to gradeschool kids and their science fair project. A better system would be a solenoid, Moffat sorta thing, where a small trigger/reference voltage, trips a solid state switch allow for full current to pass.
On another note, it is yet another pipe bomb waiting to happy. CR123 batts again, that come unprotected and create explosions like in the other thread here. The fact that they refer to them as "flash batts", which are unprotected because the protection circuit is in the flash, leads me to believe they are not protected, or the makers just doesn't know the difference.
I would wait until someone that knows what they are doing, beyond machining, offers one of these things.