SA OC 4, 22:
אם אין לו מים, יקנח ידיו בצרור או בעפר או בכל מידי דמנקי ויברך "על נקיות ידיים". ויועיל לתפילה, אבל לא להעביר רוח רעה שעליהן.
A person who has no water ... and bless al nejiut yadayim, this is useful for praying but not to ckean the evil spirit.
One of the functions1
of washing hands in morning is to clean ES, if he did sleep, but one else function is to be the washing befor prayer, as there is for mincha and arvit prayer in which there is generally no ruach raa.
See also 233, 2.
There is an halacha to wash before praying, even if his hands are clean, even if he was learning Tora. If there is no water, he needs to clean his hands wipping with a rub (Baer Hetev sk 7). The MB sk 20 explains that this last rule is not sufficient if he kbow that his hands were soiled. See Bait Chadash 232 and 92 . There is a Gemara that says that for praying if there is no water, he needs to clean with sand.
For cleanliness needed for prayer, without water nekiut yadayim is usefull. But in morning only chazal statued a blessing. The blessing is not because of the evil spirit only, e.g. if he rinse his hands in a cup, this is not good for evil spirit but he blesses al netilat, see SA OC 4, 12 Magen Avraham sk 9.