This bath bomb is amazing, I have posted about this a couple of times before. I still have a big chunk left and it has lasted several baths, all of which are an amazing and different colour. When in the water it feels so moisturising and soft on the skin. Here is a picture of my most recent experimenter bath with some lovely mix of colours.
This costs £3.95 from Lush, and is definitely one of my favourites I love this and will be buying another one when mine is finished.