On Invented Spelling
Practice makes perfect...and if you are practicing spelling something incorrectly, you are only reinforcing the incorrect spelling in your brain. Students need to learn to spell correctly, and they need their spelling mistakes corrected so they can learn the correct spellings of words.
Invented spelling came into vogue along with whole word or whole language practices, and like whole language, invented spelling is a bad idea.
An excellent article about the problems with invented spelling is found at the National Right to Read (NRRF) website: A Critique of Invented Spelling by Dr. Patrick Groff.