Purple shampoo to get rid of orange tint?

i have naturally dirty blonde hair i was stupid and wanted light brown hair so i dyed it and i didnt like it so i wanted to go back blonde and i dyed my hair blonde and it was orange so i went to sallys and the lady told me to use ash blonde to get rid of the orange tint well it helped a little but my hair is still orange and especially when i go outside i look like i have orange hair ... iheard that purple shampoo helps to get rid of the orange tint what is the best kind of purple shampoo and where can i buy it?? also do you have any other suggestions of getting rid of orange hair FAST because im going to the beach in 2 days and i dont want orange hair