Wetting agents for film are functionally similar to the "Jet Dry" liquid you use in your dishwasher to keep water spots off your dishes.
Water spots on film can leave visible marks on your final prints that can spoil your image. Using a high grade surfactant in your final rinse makes the water run off cleanly instead of beading up and causing spots.
PhotoFlo 200 is a common wetting agent for film. You mix it up, per the instructions (200 to 1) with clean water then you dunk your film in it for 30 seconds before you hang it up to dry. Just like "Jet Dry" PhotoFlo prevents water spots from forming on your film as they dry.
While virtually everybody would tell you to use a wetting agent for your film, there are different schools of though as to how to proceed.
Some will tell you to just gently shake the film to get the water off then hang up to dry. Others recommend using a sponge, a chamois or a specially made squeegee to wipe exess water off the film first.
My personal method is to attach one end of the film to my clothes line with a film clip then I pull the free end until the film is taut and run my finger over the film to wipe away the water. If you do this method, first make sure your hands are percectly clean and dip a finger in the PhotoFlo before touching the film. Be careful not to use too much pressure lest you scratch the film.
Wetting agents can form an invisible film that builds up on your containers and utensils. Be sure to wash your equipment well with hot water before putting it away to dry.
Some folks recommend an occasional trip through the dishwasher to keep your equipment clean. (Top rack only.) Personally, I don't do that. I just rinse them in a tub of water then rinse under the hot water faucet, shake off the excess then put them in the drying rack.