My hair is dyed medium brown right now, I want to go back to a medium/dark blonde. All of the information I see regarding this is for people who want to dye their hair platinum I just want a dish water blonde color.

I'm fading my hair using cheap shampoo, hot oil treatments, would soap capping work? My idea is just to do one or two soap caps/bleach baths and then use purple shampoo to get rid of any brassiness.

To lighten my hair I make my own hair lightener that is the equivalent of Sun In. You might want to try that. Some summers my hair gets really blonde. Some I just get some blonde streaks. I think you can use a hair dryer when there is no sun