Wearing a Kittel and Tallis:
A Chasan: A Chasan who wore a Kittel at his wedding does not wear a Kittel on the first Yom Kippur thereafter. Tallis: The custom of all [Jewry] is to wear a Tallis Gadol on the night of Yom Kippur. One is to recite a blessing prior to wearing it while it is still day, and continue wearing it into the night. [If one did not put the Tallis on at before sunset, it is to be worn after sunset, without a blessing. The Chabad custom is to continue wearing the Tallis into Maariv of Motzei Yom Kippur, although prior to commencing Maariv, the Tallis is removed from over the head and rests on the shoulders.]
Must one remove his Tallis or Kittel when going to the bathroom? One is to remove his Tallis Gadol and Kittel [and Gartel] prior to entering the bathroom, being it is designated only for prayer.
What is one to do if he did not don his Tallis before sunset?
He is to wear it without a blessing.
May one who already accepted Tosefes Yom Kippur still wear his Tallis with a blessing if it is prior to sunset?
Is the Tallis, Kittel and Gartel to be removed even if one is only entering the bathroom to urinate, or for other purposes?
Some Poskim rule it is permitted to urinate while wearing the above garments. This applies even if one enters into a bathroom to urinate. Nevertheless, the custom is to be stringent in this matter and remove the Tallis [and above clothing] prior to entering a bathroom or bathhouse, and so seems to be the opinion of Admur. Likewise, even if one is urinating outside a bathroom, the above items should be removed.
 Admur 610/9
 From 610/9 it is implied that the Kittel should be worn throughout the entire Yom Kippur even during times that one is not involved in prayer. No mention is made regarding prayer in that Halacha. Vetzaruch Iyun
 Sefer Haminhagim p. 124 [English Edition]
 Admur 18/3; Rama 18/1; Tashbatz 132; Mahariy Viyaal 191-192; M”A 18/2; Arizal brought in Shaar Hakavanos Derush Yom Kippur; Birkeiy Yosef 619/1; Poskim in Kaf Hachaim 18/13-14; Kitzur SH”A 131/17; P”M 619 A”A 4
 The reason: The reason why this is allowed is because it is well known that one is not wearing the Tallis for the sake of the Mitzvah but rather in order to resemble angels by wearing white clothing and garbing in a white Tallis. [Admur ibid; Bach; M”A 18/2] The Arizal however explains the reason is because the spiritual Mitzvah of Tzitzis applies on the night of Yom Kippur. [See Kaf Hachaim 18/15]
 Siddur Admur; Kitzur ibid; See P”M 619 A”A 4; Kaf Hachaim
Ruling of Admur in Shulchan Aruch: In 18/8 Admur rules the blessing may be recited until nightfall.
 Sefer Haminhagim p. 126 [English]; From Admur ibid, M”A 18/2, and Bach 18 it is implied that one is not to wear the Tallis at all on Motzei Yom Kippur; See Arizal brought in Kaf Hachaim 18/15 that one is not to wear the Tallis by Maariv of Motzei Yom Kippur, as by that time the ray of the Mitzvah of Tzitzis has dissipated; See M”B 18/6 in name of Elya Raba 18/3 which writes in name of Kneses Hagedola that the Tallis is to be worn during Maariv of Motzei Yom Kippur. See Piskeiy Teshuvos 18 footnote 10
 Admur 21/3; Michaber 21/3 regarding Tallis; Taz 21/3; Elya Zuta 21/3; Poskim in Kaf Hachaim 21/13
 See Mishneh Halachos 11/23; Vayivarech David 2/19; Beir Sarim 4/56; Piskeiy Teshuvos 21/3
 The reason: As one does not serve his master with the same clothing that he cooks in, and hence it is improper to wear such clothing in a bathroom. [Taz ibid]
 Admur in Siddur; However, in the Shulchan Aruch [18/8] Admur rules a blessing may be said until nightfall.
 See Piskeiy Teshuvos 619/4 footnote 24; 342/3
 In 18/8 Admur rules that once one has Davened Maariv he may no longer say a blessing over the Tzitzis even if it is still day. However, no implication can be made from here regarding our case as perhaps Maariv which is “Itzumo she Yom” has a different status then mere Tosefes Shabbos.
 Mateh Efraim 610/12; M”B 21/14; Poskim in Kaf Hachaim 21/13
 Mateh Efraim 610/12
 Aruch Hashulchan 21/6; See also Ginas Veradim Klal 2/25; Leket Yosher p. 6
 Admur 21/3 plainly writes that it is not proper to enter with these items into a bathroom and does not differentiate between whether one is entering to urinate or for a different reason. Perhaps, this also explains the difference in wording that by entering a bathroom he writes “it is not proper” while by defecation he writes “one must remove”.
 Aruch Hashulchan ibid