Yes use some grease on the WD bar pivot points and the ball. on heavy tongue weight applications it is OK to use a very light coating of grease on the cams. this is per reese`s web site!
From their tech support section. "Can I grease the Dual Cam Sway Control (DCSC)?
Do not grease the cam and cam arms. The Dual Cam was designed to use metal-to-metal friction. Heavy greasing of the cam and cam arm surfaces with affect performance. If noise is offensive, a very light coating of lubricant, such as Vaseline, may be used. Tongue weights over 1,200 lbs. may require a light coating of grease to reduce friction and prevent excessive wear. The Dual Cam Sway Control DCSC is not to be lubricated on the cam arms when the tongue weight is under 1,200 lbs. Instead you will want to apply a thin coat of a petroleum jelly, such as Vaseline. This will act as a poor lubricant, but works well to dampen the sound. For trailers with over 1,200 lbs. tongue weight you should apply a couple of drops of an 80/90 gear lube to the cam arm to prevent excessive wear caused by the increased tongue weight."
Here is a link! http://www.reeseprod.com/
go to tech support, click on weight distribution and sway control and scroll all the way down to the last item.