Actually, just after posting (having got all the whinging off my chest...) I wondered if buying liquid latex & making earrings with it might be easier than trailing round Camden looking for someone who sells them... So I have bought some from this rather dubious-looking internet shop (http://www.novelty-gifts-heaven.com/) because they're the only one I could find in the UK that sold purple liquid latex. Most places seem to be assuming that the colour isn't important because you're going to be more interested in the B00B135!!! that you're painting it onto...

So I think I will have a go at making some, but if it all looks too complicated for a badger of very little brain, then I could send the stuff on to you... is that okay? :)

Also (seeing yr other comment) I had forgotten about Fimo! I think I have some somewhere. Lots of exciting craft ideas for when I emerge from the other side of all the work-related doom. Thank you! :)