[Mr Bill]

My brother gave a small pencil torch and just for fun I tried heating some chips on a piece of scrap windshield. I was able to crack the glass really easily; and yes I did move the torch around.
There is no way I would use a torch on a real windshield.
I have a drystar which is very useful and manageable if used for 20 seconds at a time to dry out chips.
Some people describe it as a cigarette lighter on a stick, but I dont think I could dry out chips using a car cigarette lighter. I'd have to keep plugging it in all the time.
More accurately, it is a switch controlled heating element from a device like a car cigatette lighter which is mounted into a manual fixture so that heat can be applied with precision to a chip on a windshield.
I have never experienced a crackout using it.