Because the salt encrustation is unsightly, if nothing else, I hose out my helmet after warm weather rides. Wipe down the shell to avoid water spots and leave it in the shade to dry. If in a hurry I press a towel into the inside to absorb most of the water from the pads. In cooler or damper weather I rinse the helmet pads with the sink sprayer and use a towel.
I've heard of riders who just take the helmet into the shower for a wash and rinse (conditioner optional).