Air or sun drying is good even in moderate wind but I just lightly press down with a towel then use a hair dryer just staying far enough away so the heat doesn't damage it. I tilt my head to all sides and aim the hair dryer up onto my scalp. Once the scalp feels 50-75% dry I let the dreads air dry or place a fan 4-5 feet away or just go outside.
Reasons being: 1) the dreads tighten better if they air dry however 2) if there's any remaining bacteria on your scalp it will start to smell if your dreads don't dry in a reasonable timeframe and stay there til the next wash. For some reason drying just the scalp quicker stops that completely unless you sweat a lot in the next few days, and the dreads can still have time to go through the air drying process.. I still rinse lightly with water every other day or every day (hot/warm, then freezing cold like my washes) to loosen and tighten from getting wet then drying, and to get rid of salt from the sweat on my scalp so it doesn't get irritated and produce more oil then itch and smell.
Sure a rinse may not wash "out" bacteria on the scalp w/o your cleaning agent (baking soda for example), but you produce less oil/irritation in the long run and letting the bacteria sit there with that sweat at your skull without ventilation will be pretty grody. If you don't want to rinse and your scalp is sweaty, just shake your dreads to keep them from being flattened so you get some extra air, and preferably sit in front of a fan/wind to keep it dry occasionally.
And obviously if you did have a wet scalp for too long, the roots would get extra oily and keep the dreads flat against the scalp, holding in extra heat which leads to more sweating and they'll also soak up the oils/bacteria, thus making the problem even worse cause then the scalp DEFINITELY won't dry very quickly, THEN you'll have less progress dreading cause they're soaked in oil/possible stench til your next wash. And finally you'll need to do an extra thorough job the next wash to get all those oils out and get your scalp clean.
I know that was a little long of an explanation but I sweat a lot on my scalp and produce oil quicker than most and it's taken me a while to figure out what the problem was..