Mmmmmmmm, carbide. I feel like I'm on one of those *other* boards.... ;-)
Yes, that's a good idea - especially if you have a ton on hand. Those ceramic/glass fibers do just as much damage to your lungs too.The coolant will also keep the fibers from floating around too.

I spent half of my life drilling FR4 and other insulators and I am finally learning why. The electronics are a lot more fun than milling the boards!! And it's funny, I can make them BOTH smoke!

good luck with your product. What are you making, by the way?