If you have pistons, spider webs, and any gravity blocks,
So let's get started!
Firstly, place the piston in any direction
Secondly, place spider webs within a block in the direction of piston ejection
Thirdly, place any amount of sand on top
Fourth: Place a button next to the piston
Fifth: Remove the bottom sand
Then click on that button, and you will find that the sand will expand and there is an item with a string