Crystalline (table sugar). Powered would likely work as well. The baking soda destroys them from the inside out, basically blowing them up. Roaches have strong stomach acid, but they cannot "burp" so the baking soda creates a mini explosion inside them. Fitting end.

Thanks, I'm going to try this.

Just to be clear: "baking soda" is Bicarbonate of soda (aka. bicarb soda, sodium bicarbonate)?

Mix in equal proportions?

It's a dry mix, not with water?

Yes, 50/50. Plain old Arm&Hammer. Dry.

Thanks. I would have thought the large crystals of sugar would be easy for them to differentiate... but perhaps the baking power ia so fine-grained, it coats the sugar.