Spelling woes.

I am having some difficulty trying to figure out a painless way to teach my homeschooling 16 year old how to spell.  He's so smart and he loves to just read and absorb information that with any other subject, I can just hand him a book and off he goes.  Spelling is different.  Spelling is one of his glitches.  (The other one is handwriting).   I think he would do well with learning the etymology (word origins)  of the words to see why it is spelled the way it is.  I thought that The Logic of English would be a good fit for him, but he finds it mind-numbingly dry, at least the way the lessons are presented on Youtube. We may just have to just accept that it is going to be kind of painful or kind of mind-numbing and go with it, but meanwhile, I am looking at etymology as a key to spelling because he's fascinated with word origins.  I found a couple of really cool videos here  but only a couple, not one for each of the word families.  I am open to suggestions!

Anyone!?

Has anyone tried English from the Roots Up?