where are you going to hook a ground to a plastic cased machine? or a plastic collection container???
static electric is NOT going to automatically jump to ground just because one might be closeby.
If it bothers you that much, open the machine up,. wrap the inside of the case with tin foil, with a wire going to the ground wire if you think it will help. Maybe get a metal bristly type brush, like on the bottom of a door or something to have the grounds 'whisk' by to pull off the charge on them.
Or just thump the thing and knock the grounds into the bottom and empty it.
You could get one of these static wristwraps electronic workers use, put it around the mouth of the thing and plug it into a ground, might help too.
Plenty of ways of dealing with it
Aaron