Advice on removing a toner
I did a color correction a couple of weeks ago. The canvas still had a little bit of uneveness, but overall ended up a very yellow level 8/9 blond with a pink/peach hue. I toned down to cover the uneven spots. I toned with shades eq a equal parts 10gi,6gi,8gi (so it would be an 8gi) totally 4oz, and a dash(.2oz) of 6gn to counter the pink. I think I added a little too much gn and it turned very mushroomy, and darker than I wanted. (It had been 10 hours and my brain was not taking into account the porosity of the hair). 100% my fault, and I offered to fix it, but my client left on vacation the next day so they decided to try and fade it at home.
They've been using hot water and clarifying shampoo, but the tone isn't getting lighter at all. I'm having them come in tomorrow. My plan was to use a CPR to pull the tone out, but my client said they don't want to do that again, and asked me to please do something else. (I think they struggled sitting under the heat. And I get that, its hot this summer)
Does anyone have any other suggestions or advice on how to remove the toner?