The Shulhan Aruch (Orah Haim 4:18) writes that one is required to wash his hands after bathing his entire body, in order to remove the Tum’a (ritual impurity) from his hands. However, unlike on other occasions requiring hand washing, one does not have to use a utensil when washing his hands after bathing.
It should be noted that this applies even when one bathes or showers in a room that does not also serve as a restroom. If the shower or bath is located in the restroom (which is often the case), then one must in any event wash his hands to remove the Tum’a which rests upon his hands in the restroom. Halacha requires washing one’s hands anytime he enters the restroom, even if he does not perform his bodily functions. In fact, if a person merely places his hand inside the restroom – such as to take something from the restroom – he must wash that hand, even though he did not actually step inside.
Strictly speaking, one who enters the restroom does not have to use a utensil when washing his hands. It is, however, preferable to use a utensil when washing for this purpose. Some people have the custom of washing three times in alternating fashion after leaving the restroom, just as we do upon awakening in the morning, but this is an additional level of stringency that is not required according to strict Halacha.
After entering the restroom, one should wash from a sink situated outside the restroom. If the only available sink is inside the restroom, then one should try to at least dry his hands outside the restroom.
Summary: A person who enters a restroom must wash his hands after leaving – preferably with a utensil – even if he did not perform his bodily functions. If the only available sink is inside the restroom, he should at least dry his hands outside the restroom. A person must wash his hands after bathing or showering even if the bath or shower is not in a restroom.
