Copper red to blonde?

So I have natural dirty blonde hair that I have been having professionally colored for a long time. I started out just doing highlights to bring out my blonde but in middle school (about 5 years ago) my mom let me go chocolate brown. From there I went to an auburn that my hair dresser created for me using a brown and a red color. It was a dark brown with red tones shining through. It looked really awesome and I had that same color done to it for a couple of years about every 4-6 months sometimes longer in between. The color always faded the same and it would fade to a lighter copper kind of color. I recently just went back and got caramel and bleach blonde high lights all over, however this is not what I wanted. I showed her a photo of an all over blonde color (Lauren Conrad) and she gave me highlights which left me with a stripey top and the same copper red at the bottom.

I looked online and was going to bleach my hair until the lady at Sallys freaked me out. So I looked online again and read someone saying to use Loreal Blonde Supreme in light ash blonde because it cancels out red and orange tones. So I went to CVS and found it and the box says for red hair that it will make it blonde with gold tones. My hair is sort of a mix of colors. My roots darkened as I got older so they are like a dark blonde/light brown almost. I have naturally strawberry blonde hair so that sort of peeks through in some spots especially in my roots and then I have the highlights my hairdresser added. So I am currently doing a strand color test with the Loreal I bought. I also got a toner shampoo (purple)

All in all I am just wondering if anyone has ever used this product, or if anyone knows about cancelling out red and going blonder. I'm hoping this works out because my hair looks terrible with these highlights.

Sorry if this was weird/confusing to read.