Especially since here in N.c. The winters are brutally cold, so there is virtually not rinsing or bathing right now (which bugs me because she is always dirty).
I as well only bath my horse before a show, or on a hot summer day just to pass time and give your horse that amazing smell:)
If a dirty horse REALLLY does bug you though, try spraying your horse with a coat spray, waiting maybe 30 seconds, then brushing through it with a dandy brush. That has helped me get my horse squeaky clean (water free) for a while now:)