I think that you should have not gotten off the subject so quickly. You need to make sure that they understand that while yes it smells good, it is for adults only because of a chemical it contains. Tell them if they would try it they would become sick, etc.
I do not have children but it seems that if you try to make things a mystery, it will make them want to try it all the more. Be open about it, explain, answer questions. You can't just tell them not to do it because that will probably want them to do it all the more. When I was a kid, if my parents told me not to do something without a good explanation, I would want to do it all the more.