By barley seeds, do you mean the grain? Typically, barley fed to horses should be processed in some way, to make the nutrients inside the hard hull of the grain more available to the horse. Rolling, crimping, or other processing can increase the digestibility of the grain. The grain does not need to be soaked unless you need to decrease the sugar and starch content. Soaking for 30 to 60 minutes will leach out the soluble carbohydrates. Such a practice may be needed to deal with an overweight horse or one with metabolic problems. Keep in mind that you must drain off the water that contains the leached sugar and feed the grain only.
