hi, I have used their henna's quite a lot. No, it doesn't radically change the colour of your hair..it's not meant to. It gives a reddish hue which after all is what henna is for. It also made my grey hairs (did I really admit that...lol) a golden colour so I appeared to have highlights too.
You don't have to grate it, but it needs to dissolve before you apply it...so it takes less time if you do.
If you use this you should be aware that although it does fade, if you apply a normal colourant over, within a few weeks the red will show through. (If you read the advice on the side of hairdyes, they say if you have used henna, you need to have the hennaed hair cut off.)
Biggest draw backs- it's really hard to get it all out, and I have never been too sure whether it made the ends of my hair go strawlike, or if that was just my hair in poor condition.)
using : a varied assortment till I work out what the heck is going on
scrunch or plop with old t shirt
Garnier endurance hold gel

Mop clean system- hair feels stripped after using it. Anyone want it? then I can justify getting something different.

4 kids, 1 husband, emigrated to Australia -filling in forms, buying a house, sorting out school...and trying to track down hair products

= no time