Removing old stain from a log cabin

Sorry, not a deck question but I figure exterior stain is exterior stain and I'm desperate! I have a 60 year old Chestnut log cabin in NY that is in desperate need of a stripping and re-staining. I tried a gallon of the Sherwin williams deck stripper with a pump sprayer application, with a nylon bristle brush to rub it in nice. Let it sit for 20 minutes then power washed it off. It wasn't nearly powerful enough (see pic of final result). I need something that I can apply basically the same way that will really remove the old stain.