The reason employers and other like to do hair testing is because it is more effective. The metabolites and toxins can stay in your hair for years. There really is no way to completely get rid of that either.
I would suggest finding some kind of shampoo or product to mask it for now. Those products arent always guarenteed to work but it would be better than nothing.
The same people that manufacture the Quick Fix also have some shampoo for hair test. I have never used it so see if you can search on google for it ...its also on their website urineluck dot com