Seeing the beginning of this made me realize how simple it is to make one of these. I would of course fill it with something else than fossil-plastic “beans”. Why not use real beans and air it out if it gets wet? Or wool either a type that filts or one that does not.
The advantage of wool is that it provides insulation and a nice warmth – beans do not. This is useful during the cold winters, one could make two and alternate or just switch the filling (wool=winter,beans=summer).