Hubby will be back in Oz this month. I would like him to bring back eucalyptus and tea tree oils for me (I buy them from a plantation in Tumut). I can buy these oils in bottles of min volume of 100ml, but how many bottles of 100ml can hubby take in his carryon bag? Since these oils are expensive, I don't want customs to confiscate them at the last minutes! Maybe it would it be safer if he put them in a checked bag? Hubby likes to travel light (with carry on only) so I may have to pack a spare bag for him to check in.