yea, like others have said, it will help but not solve the problem....
i have a home made deal i use. i got a little longer 2" receiver that has enuff room on the shank between the hitch on the truck and the ball part. it's just square tubing with an 18 wheeler flap cut in half [ the flap is very firm. it has small steel rods molded in it, like an anti-sail flap] and mounted to both sides. it works very well with heavy slop. i have to drive on a dirt road and it definitely helps keep rocks down!
i used 1-1/4 square tubing for the cross piece and a 2" id square piece about 2" wide that goes over the reciever. i had a nut welded to the 2" part, and i tighten a bolt to keep it firm. it looks like crap but works pretty good. Nate