I first saw this product at Kilpatrick's Christmas open day, where a small mixing bowl had been filled with a satifyingly goopy pink gel. I tried it for myself a couple of weeks ago and really enjoyed the spa-like treatment. Run your bath then add the first sachet to the water and mix around with your fingers. It will gradually turn into a soft, creamy gel, while the water turns a fuchsia pink. Don't stand there mixing all day though - it's not gel in the viscous, rubbery sense, more of a thick water, with gel beads. And do watch when you're stepping in - it makes the bath VERY slippery.
Once you're in, it really does feel like a spa treatment. The beads that gently buff the body - great if you're feeling stiff or sore - and it left my somewhat weather-worn winter skin feeling much softer. On top of that, it's been proven to maintain the water temperature for up to 4 times longer. When you're ready to get out, you pour in the second sachet and mix to turn the bath back into water.