DIY hull mattresses

Just came across this and thought it belongs here. it’s pretty cool - they sell the fabric tubes, you buy the buckwheat hulls and fill them. You can combine them to fit any shape:

If you want to buy the buckwheat hulls to fill these things you can easily get them in France and probably I think Venga - Recharge de balles de Sarrasin BIO 15,5 l - Sebio