Furinkazan

It looks like if I read further, you mean kata in particular. I think that would require paying for private lessons if you're trying to bypass the full curriculum. I'll play devil's advocate and say that I don't disagree with the instructor. To quote Terry Silver from Karate Kid Part III, "Did you come here to teach or to be taught?" Even in the first two Rocky movies, Mickey had to assert his position over Rocky whenever Rocky expressed disagreement with Mickey's training methods. And Rocky did the same thing with Adonis Creed in the first two Creed movies. I don't think it's unreasonable that the instructors running the school don't want someone who hasn't paid their dues hijacking their classes. When we speak of learning from lower ranks, it doesn't mean someone of lower rank assuming the role of the instructor. It usually comes in the form of the person of higher rank seeing a technique that the lower ranked student used, and specifically requesting how to execute it. If you have a technique that you want to share, I think sparring is the best time for it. That's when you'll get the feedback you're looking for.

My tried and true method: 1. Mix 1 part dish detergent (preferably clear, blue, green, or yellow. I worry about red "kool aid" looking stains from other colors) and 1 part peroxide. 2. Dip a toothbrush into the solution, and use the toothbrush to brush out as much of the stain as you can. 3. Put some baking soda on the wet area you just brushed, and rub it in with your finger. 4. Let it sit for an hour, clean the toothbrush. 5. Mix 1 part water and 1 part white vinegar. Also, have a separate cup of water and a cloth. 6. Dip the toothbrush into the vinegar solution and brush out the areas with the baking soda. You'll want to use the separate cup of water and a cloth to removed any baking soda from the bristles, as you don't want any baking soda to get into the vinegar solution. 7. Throw the gi into the washer. Every stain you can possibly imagine, I've removed with this method. Blood will take few washes after this to go away completely, but it still works.