Arnold's Wrecking Co. (1973) on Netflix

Arnold Berman is a klutz. Just ask his cousin Kenny, who has to put up with him over summer vacation from college. Arnold has to be seen to be believed: an uptight, unreal, super-straight Business major who's a whiz at accounting and a failure at everything else. Kenny and his pal Rollo turn Arnold on to a little grass to loosen him up, but they don't realize the demons they've set free: for the now-swinging Arnold becomes a pothead Horatio Alger and soon has them all in the midst of a multi-million-dollar grass-dealing firm complete with snazzy executive offices, a fleet of delivery trucks, group insurance, and a little league team. All of this does not escape the attention of either the local police or the local "organization," and the result is a free-enterprise free-for-all in which the customers are as high as the company stock.