You can use just about any glue stick, as long as it's washable. Fons & Porter also makes a glue stick and refills that are easier to find than poor Sue Daley's product. I've used their refills in Sue's stick.
Just wait until the glue manufacturers catch on and start making skinnier sticks....
Edit: just looked at my glue stick and realized it's NOT one of Sue Daley's - it's a Sewline product!