A sway bar, or friction bar, is just that. It keeps the trailer towing smoothly but does not do anything to distribute weight. 

Amen to that!  This is something that is often ignored, resulting in trailer sway.  Using our 177 as an example:  loaded weight is 2940 lbs x 10% minimum weight needed on the a-frame (tongue) would be 323.4 pounds needed.  Using a Shurline tongue weight scale - it reads 340 pounds, more than the 10% needed; the result is no trailer sway, regardless of weather or road conditions.

Any friction bar works attaches in the same way.  A plate is attached, normally bolted, to the a-frame of the trailer and another plate is bolted together with the ball/receiver on your tow vehicle.  The friction bar attaches to these two points by using a couple of clips.  The only thing that must be done is BEFORE backing up, release the pressure on the friction bar, otherwise it will be permanently ruined. 

Any more input would be great. 

I cant tell how that Curt friction bar works. what does that attacth to. 

If you are referring to weight distributing hitches (WDH) that is up to you.  Many swear by them or at them as they have been known to destroy the front end of the r-pod by separating the aluminum structural members that hold it together.  If you own a unibody vehicle, avoid these at all costs. 

For myself, I have never used one.  Our fully loaded 177, prepared for a 30 day journey with 36 gallons of water (tank behind axle) weighs in at 2940 lbs.  With over 53,000 miles on it our tow vehicles have included: '94 F-150, '08 and '13 front wheel drive Explorers, '11 and '17 F-150's.  We have towed through snowstorms and blizzards, sleet, hail, cross winds in excess of 25 mph, and of course, heavy rainstorms without incident.  We do, however, utilize a Curt friction bar.