Hi John,
I'm sure people will come up with alternatives, however I found a product called 'Citraclean' made from extracts of Oranges, (and I'm not taking the Piff)
It's about £8 for 5 litres and has a load of uses, your problem being one of them.
I got mine from Greenham Trading ,(you should find them if you do a search, they are a National Co).
P.S. Funny thing is that it also removes 'sticky labels', so when you splash some over the container it comes in....
the Instruction for use label falls off
At least proves it works
Les