How to get rid of last bit of green blue dye

[hoodeeharhar]

I've got fair red/ blonde hair and used a 10 washes turquoise semi permanent dye.
It looked gorgeous and I loved it, but now want to get back to natural.
It's been more than 10 washes, its at the faded stage, any ideas to release the last tint?

I've used bicarbonate and dandruff shampoo. It is just a case of repeat?

It can look a bit grey/ mouldy now in certain slights

Only thing that worked for me was a red. Its relentless. It's still there!

I've got the majority out. I'll post a pic of how it was