Green to blonde?

I had bleached ash blonde hair, and then dyed it with manic panic voodoo blue. After it faded a bit, i started updated to color every month or so with manic panic venus envy to make a deep teal color. About a month ago, i started trying to fade the color out. I started out with mixing  baking soda in with my shampoo, and it definetly helped, but slowly. Once a week i leave the shampoo/baking soda mix in my hair with a shower cap and apply heat with a hair dryer for extra oomph. After a while though, i stopped seeing any color in the water when rinsing, and stopped seeing any more fading. I decided it was time for a bleach bath. It lifted a bit, but not enough. I just need to eventually get back to a natural blonde color. What should i do next without damaging too much?