This guy sells braids made out of dried Sweet Grass
look toward the bottom of the page.
I never tried the braids, just bought my live plants, but if they are not old and stale, they should do OK for the scent. Sweet Grass smells sweet for remarkably long time. Still, ask him for this season's braids, not last year's leftovers.
I guess you will have to un-weave the braids to separate the individual blades, count off 50 and go from there.
If you decide to try homemade Zubrowka follow the recipe to the letter. Don't try to improve on it by using more grass or more concentate per bottle.
I spent quite a bit of time getting it to this point.