Firstly can I just say hello to all the beardys, big fan of your work.
I'm a trained hairdresser so I hope you don't mind a few words of advice:
I've tinted many a beardy and because of the type of hair it is it the dye can fade quite quickly and it will grow out in 10 days.
Dye that's too dark can make a handsome man look like a David Guest body double.
It's exactly the same product as eyelash tint which is about 10% of the price. If you're going for it, it's a worthwhile investment. For the same price as a fortnights worth from Boots, you can pay the same to get several months worth at a hair supplier.
Oh and if you ask a lot of mobile hairdressers do it for around £4.
Best of luck, put Vaseline on your nostrils!!
(Oh forgot to say, I know it bugs guys but women who appreciate a face rug really don't care about the colour. A ginger tint is sexy)