Does your tupperware feeding container fit in the frogs cage? Even if it's squishing a plant or two, just having the pet sitter put the entire thing in might be easiest.
You could consider trying the http://www.frogforum.net/vivarium-te...owl-trick.html
It's definitely not always an option
. Even if it was, I think it's still a good idea to set things up to be as smooth and simple as possible for your temporary care giver (like you're trying to do
).