Hola!
A wonder mask for under £2? YES IT'S TRUE.  I have tried out masks from every corner of beauty - low-end to high-end, to in-between-end.  And may I say, this comes out pretty much at the top of the list.  Under £2 (currently on offer), so I have stockpiled a little!  
This is quite simple a clay mask, where the Kaolin is pretty much at the top of the ingredients list, so at least we know it contains a hefty dose of what we are using it for - the clay.  It works in 3 minutes.  Yes, that's right - 3 little minutes, I've tested it.  You could literally put it on, brush your teeth and wash it off.  But sometimes I leave it on longer: basically it doesn't matter, the product just works.  
When applied it is a whitish-greyish colour, cooling on application, drying to a tight-face-type-look.  Washed off, skin is plump, soft, soothed, cleaned and any spots are hugely less angry.  Basically a real skincare staple that should always live in your stash!
Please let me know if you've given this a go!
Love A.x