I have a friend who bought a house and established a sizable garden spot. Once he established an area, he added a dump truck load of gin trash, worked it in well and he has had an awesome garden ever since. That was several years ago and I think he has added more gin trash a couple of times since then.
Cotton seed meal is a FINE fertilizer...about the only downside to using mill trash might be an occasional uncrushed seed that comes up as an undesirable weed in the garden.
I would think just put it out over the area, and till it all in...as it composts, it'll improve the soil for the years to come, too, even if your rows end up slightly offset from where they are this year.
This would be more like all the stuff leftover after the cotton is ginned and the seed (or most of it) removed. A little cotton fiber and a little seed meal, bolls, stems, leaves, weeds, etc...it gets pretty chopped up in the ginning process, and would make an excellent addition of organic matter to soil.