Does the second washing done after using the bathroom follow the regulations of washing upon awakening, or does any washing suffice?[1]
One is to wash following all the laws and details of the morning washing [three times inconsecutively with a vessel, with Kosher water etc]. Furthermore it is customary to use a towel while washing this second time in order to properly adhere by the law explained in Halacha 7J.
[1] Ketzos Hashulchan 12 footnote 9 and so is the accustomed practice
Background:
The morning washing contains various laws as explained in length in the previous Halachas of this chapter. While it is clear that one must follow all these laws and regulations while washing the first time nears one’s bed without a blessing, it is unclear from Admur whether these laws must be followed when washing the second time, after going to the bathroom, when the blessing of Al Netilas Yadayim is recited. Seemingly it would appear that after the bathroom one is merely required to wash his hands as is normally done after bathroom use without being particular in the morning washing laws. This is due to that one already fulfilled the morning washing and the blessing of Al Netilas Yadayim is going on this first washing [although with an inevitable interval of time as was explained]. The Ketzos Hashulchan ibid debates this matter and concludes as follows: The second washing after the bathroom must be performed with all the laws of washing upon awakening as the blessing is being on this second washing as opposed to the first washing. The reason for this is because by going to the bathroom one has nullified the effect of the first washing, which was for the purpose of preparation for prayer, as now he may not pray until he rewashes. [See Halacha 2. Thus although one has removed the impurity with the first washing, he has not prepared himself for prayer which is the main reason behind the recital of the blessing, and therefore the blessing can only be said with a proper washing after the bathroom.] The Ketzos Hashulchan goes on to explain this understanding also from the wording of the Siddur of Admur. He concludes however with a Tzaruch Iyun.
Other Opinions: The Ketzos Hashulchan 2:9 writes that one is only required to wash his hands one time for the second washing, after leaving the bathroom. The Kitzur SH”A 2:7 has a similar wording although it can be interpreted differently. Practically in the footnotes the Ketzos Hashulchan rules as stated above.