can static grass applicator use manila hemp,instead of static grass?

I don't think so. Static grass is made from synthetic material like nylon, rayon, or polyester fibers. This material can hold an electrical charge. That, and the ion generator in the applicator, make the "grass" stand up when it lands on the surface. Any thing else would most likely just fall over. You might have more success using a synthetic rope and cutting that up into bits...cheap, but laborious.