With many natural fibers, they lengthen slightly as they get wet, and shrink a lot when dried. I noticed this, and decided to find out...
3 major benifits- less harsh on hands(sisal), MUCH tighter weave, Stretches MUCH less.
Other benifits I have not figured out yet...
Anyone else try this? I love this technique now! As of now, I have made 5 slings wet-weaving. 3 rocklarics from jute (2 are drying now) 1 rockman, and one creepy-knotted sling.
other benefits- you get a more consistant braid and weave, and the braid is tighter, whips are tighter, and the cordage is easier to work with.
-Squirrel
Will post pics tomm.

Yeah, you're right, damp fiber is easier to work with. I've been spraying my hemp and jute slings with water as I braid for years

Good suggestion

I braid them extremely tight until they are rigid and soak them after they are finished as it relaxes them while keeping the tight braid.

Damp cords are great, soaked cords will expand and shrink a lot and your braid will actually be more loose. That's my expierience at least.

Find a balance and you'll be set. 

I've used a damp, not wet method for sisal and cocount. The right moisture consistency seems best when the fiber feels cool when you touch it to your lips but not soaking wet. Not dripping wet. With some types of hemp I have found that the strands are almost a little slimy which is why I do it damp and not wet. Also, some hemp really stinks when it gets wet which doesn't make a good braiding experience for me. I have also found that weaving damp fiber is harder on the hands.

My preferred method is to dampen the fiber with water and hair conditioner or leather conditioner that is mostly glycerin. Glycerin soap works good too as does saddle soap. To keep the fibers at the right moisture content I use a small spray bottle with a water and conditioner or glycerin mix.

The only drawback I have run into when using short fiber that has been twisted together to make long cordage for braiding is that if too much lubricant is used, the individual strands can pull apart easier. It doesn't seem to affect the finished sling and sometimes you have to be careful not to pull the individual strands of the braid too tight when braiding.

Glycerin doesn't seem to affect the sling when it's dry.