Maybe you should have phrased the question differently. How do you stay dry in the rain?

Then we would be talking about things like using a durable pack liner, waterproof sacks for sleeping gear and clothing, pack covers, ponchos vs rain jackets, and the point at which one realizes the weather isn't just a passing thing and pitches the shelter. If you can work out how to stay dry, you don't need to worry about trying to dry stuff. If all that's wet is your rain gear... what's the problem? roll it up inside out and leave it in the vestibule.