After quickly showing the (female) LUSH store worker the length of hair to be dyed (approx 21" at the time) she recommended buying/using 3 bars. In all honesty, 3 bars was a lot, so my sister and I both decided to share, using 1 and 1/2 bars each! Perfect (any more and the weight would've definitely had our heads rolling on the floor). Preparing and applying is a little bit tricky and it's definitely worth having someone around to help. We remember reading that you have to apply newspaper all over the house and wear old clothes, etc. It's not that much of a clat. A chair with some newspaper underneath (to catch anything that falls), a bit of vaseline for the ears, a towel around your neck covering your clothes and clingfilm for the end is enough. We left it on our hair for about 3-4 hours. Washing it out in a sink is good and thorough and you'll probably notice that a second wash is needed. Our natural hair colour is the colour of milk chocolate (google that actually) so the colour pay-off was a lovely subtle red and was very natural looking, especially in the sun (colour develops as time goes on). If you want a more noticable colour, then caca rouge is what you're after. We continued to notice the red after 2 months so it's definitely worth the money.
Easy? Easy enough. Would we do it again? Yes!
Narrated by Abu Rimthah:"I went with my father to the Prophet (ﷺ). He had his hair hanging down as far as the lobes of the ears stained with henna, and he was wearing two green garments." [Abu Dawud 4194]