Hyperventilating for metal saws

I use a Japenese wood hand saw that has a ‘blowhole.’ It blows
dust away by having a ball inside that blows out a small hole as
the sawing action provides the movement up and down for the ball.
I suppose the same principle could work for metal saws.

Jackie, That japanese saw sounds like a great tool. Can you tell
us where to get one? I’m not so great at rigging things, so I
try to keep things simple. I too am tired of brushing away the
dust. Thanx Linda B.