I am assuming you mea n after diving. This is what I do
At the end of the day of diving I rinse the reg in fresh water or if possible soak it to remove any salt water. I flush water into the exhaust hose and out the reg. Place the reg in a shaded spot to dry.
At the end of the diving for an extended period (not diving that reg for more than a day or 2) I remove the hoses at the cans and flush warm water through the hoses, making sure to completely fill them by plugging the mouthpiece. Once I have the hoses completely washed out inside I sling them to remove as much water as possible then hang them so that any remaining water can drain out of them,. Occasionally I will return to them and attempt to sling any more water out of them. You do not wan t to store them unless they are completely dry inside, otherwise nasty things can grow in the hoses. I do not attach them to the reg until I am preparing for a dive.
With the hoses removed, I thoroughly rinse the cans in warm water ( with the dust cap on). I fill the cans with warm water, slosh it around, dump it out and repeat 2 or 3 times. It is not unusual for some water to get into the cans. That is not a problem but leaving saltwater in them for extended time is. Leaving salt water in the cans for extended periods will cause a lot of corrosion. I run water through the exhaust horn as well. With the rinsing done, I shake the cans to remove as much water as possible then place the cans on the horns with them facing down so that any remaining water can drain. Once the reg is completely dry inside I store them with the hoses. If you have a band clamp on the reg, separating the halves and allowing them to dry is not a bad idea.
You might want to read this thread as well, it was a recent discussion on salt water in a reg and cleaning them. viewtopic.php?f=26&t=9644