Crispy skin spatchcock chicken with baking powder

[lc]

I'm thinking of trying spatchcock chicken later this week.  I thought about cooking it low and slow but, after looking at a lot of different methods/recipes, I think I wanna try the baking powder method to get really crispy skin and it looks like that would need to be cooked on high heat.  I've found quite a few praises of the baking powder method but none with details, i.e. how much to use.  Some say to mix it with salt as part of a dry brine and others say just to sprinkle it on the skin right before cooking.   Has anyone here used baking powder on chicken skin and, if so, were you happy with the results and could you share your method?  What heat did you cook it at?

[billsfan]

After I spatch it I season with whatever I'm using (really like Slap Ya Mama), and dry it on a rack in the fridge for 4-6 hours. Then I roast it indirect at 350-400 until it hits 160 and pull it. It stays crispy even if I let it sit for a bit