It seems like Acnecide 5% w/w gel is now the most readily available, which is what I was given when I asked for some over the counter at my local chemist last year. It still made short work of some nasty inky stains she had, but some of them took more than one application. Might be an idea to try a dab on the soles of her feet first, as that worrying post from Indigo about tpe composition on TDF a few years ago springs to mind. Don't know how much of that still applies these days, but better safe than sorry