I have not, but I use other stuff. I have a huge hypertufa planter that sits by my back door. It is half filled with soy based spray foam insulation and other recycled foam. I can't see that aluminum would be a problem, as long as the material didn't pack and in the end hold water, it should work.

I have seen what might be considered even crazier things.

For example, see attached link - using PVC and wire mesh to create self-watering pots, essentially. Interesting (if not ingenious) idea.

Here is a link that might be useful: Bill's figs - pot culture

sure. aluminium soda cans placed upside dow can be practical, if you think your planter is too deep.

I have used those commercial white foam blocks that they pack PC and other things with, in the past to save soil in upside down tomato, to make it light weight, insulate from heat and keep the soil cooler. I would still used those instead of soda cans.