Mcat,
Dying hair can be tricky if you're not used to it. Use too much and it will run down into the knots and then you've botched the mission. Some customers order just the front 1" of #22R and then dye that to their hair color. There is not extra charge for that. But unless you're really hung up on knots the factory does a great job with knot bleaching and you save yourself the hassle.
Regards,
John