Eucalyptus oil on a cotton bud (not ball) will do it, just a gentle rub around. If you think that might be a bit strong (or too close to sutures)? neat dishwashing liquid?
:yeahthat:

Was going to say eucalyptus oil - my mother swore by it. Or maybe some "disolve it" from the cleaning isle at the supermarket - it is a citrus based cleaning liquid - this may be a bit too strong.