How do I get the smell of sick out of a leather sofa?!

[Cavs]

So, dd was sick all over the leather sofa last night and I thought that it would be relatively easy to clean up. So, once I'd got it all up there was still a bit of smell, so I used Dettox (probably not great for the leather but it's only a cheap one!) and thought that would fix it. But this morning I could still smell it in the gap between the two seats. I've since used washing up liquid and really hot water and dettox again and it still smells a bit. Tbh, it's only if you stick your nose right near it but I've got friends coming round tomorrow and would hate for them to get a whiff of it!

Any suggestions?