Someone told me that technically one needs to pour water on each hand only once since we use large quantities of water. Is there a halachic source for this? I heard that the requirement to pour twice ...
When washing your hands for Netilat Yadayim, how much water do you need for Netilat Yadayim?
I am after a source that allows one to treat one's house as all within four amos l'chatchila, with respect to nagel vasser (hand washing in the morning).
OC 181 (4) MB  says that when washing mayim acharonim one must wash up to the second knuckle and using a few drops does not fulfill the mitzvah at all. Shulchan Oruch HaRav 181 (4) says there is ...