Well I got my Molasses (which is a mixture of honey, other natural molasses, and glycerin) in Germany and I can't find any online here.
But seeing that you live in the UK, go to a hookah store and see if they have any or check out an online store.
I also heard that honey works, I've never tried it though.
This is the one I have. This shop ships to UK also, if you can't find any at a local store or UK online store.