I'm going to lead a workshop for kids about decorating gingerbread cookies with royal icing. It will take place at a cafe, so I need the icing to be as dry as possible as fast as possible, otherwise the kids will not be able to take the cookies home or the icing might get broken on the way.
The problem is that I have very limited space and resources, for example, the cafe doesn't have an oven, so I can't dry the icing like meringues. There is a microwave, but I haven't got one at home, so I don't know if it will work or how to set it. I could bring a fan, but will a fan be enough? Nobody I know has a dehydrator, so this option is also out of question.
I plan on making the icing as stiff as possible while keeping it liquid enough for the kids to pipe on the cookies, but my experience says it will still need 2-3 hours before it's hard enough to be carried home more-or-less intact. Is there anything more I could do?