I'd like to add something too. Try using old toothbrushes that have the more stiff type of bristles. If you can't reach far enough with one, fasten a wooden popsicle stick to it so that you now have a longer handle!
I have been dissolving one of those Cascade Complete pods and soaking most all my bottles clean of practically anything that is stuck on the glass surface.These are the ones that require no rinsing of the dishes before you chunk those dirty dried food stuffs into yer dishwasher. But beware they must have a high caustic content because if you dry yer hands off on yer pants or bath towels... it will eat yer clothes up!. nearly as bad as battery acid!