I got this included in my Sanctuary offer of the week at Boots before christmas but I've only just recently given it a whirl.
I am a fan of charcoal and thermal face masks as I have combination skin and it helps to balance excess oil and draw out any nasty impurities.
I got a sample sachet of face mask but there was plenty in it. If Id have used it a little more sparingly I'd say I could have got 2 applications out of it easily. The consistency was very very thick and as it is charcoal it was a dark grey colour (sorry my photo of this has disappeared). I left it on for, like it suggests, 5 minutes and then rinsed it off with warm water. It left my skin feeling very soft and not shiny or looking oily.
I would use this again but I would perhaps get the larger tube as a little goes a long way.
This is available from Boots and is £10.20 for a 100ml tube or £2.03 for a 15ml sachet the same as what I had.