I've used Brass Banisher to reduce the yellow in my blonde highlights, but I am still not satisfied and am forced to use Roux's "silver lining" temporary colour/toner every shampoo to get the right effect.  Can I use the Brass Banisher a few more times?  Would this increase the brass banishing effects?  I am thinking of weekly - until I get the right tone.  Also, the instructions recommend that you only leave it on for 10 minutes max.  If it has no damaging ammonia, why not leave it on a little longer?  If they are afraid of over correcting and getting a blue or green tone, wouldn't it be okay to try gradual increases in application each time you used it?  Thanks.