Noch do a static grass puffer bottle which gives the 'grass' a slight charge (friction through the nozzle). I haven't used one myself but, applied straight onto glue, the stickiness of the glue should hold one end in place while the rest is repelled from the surrounding 'blades' so they stand upright. Same principle as Cherno's bottle, above, and probably exactly the make he is using.
The physics is sound (I teach it!), but I'd be interested in knowing how it goes in practise, too.