Q. 1) When a man gets a haircut L’kavod Shabbos and then Toivels (immerses in a Mikva), are the inevitably remaining detached hairs a Chatzitza (interposition)?
A. Horav Shlomo Miller’s Shlit’a opinion is that those hairs are not a Chatzitza for any Tevila.
2) May one Toivel L’kavod Shabbos Thursday night if necessary?
A. Horav Shlomo Miller’s Shlit’a opinion is that even thou he usually immerses on Friday morning, when necessary it can be done the night before.
3) Is there value to Toiveling sometime Leil Shabbos, if one didn’t do so before Shabbos?
A. Horav Shlomo Miller’s Shlit’a opinion is that it could be done, as women do.
Many Chassidim also immerse on Shabbos morning.
4) Is it carrying when ones’ beard is wet after Mikvah?
A. Horav Shlomo Miller’s Shlit’a opinion is that it is not considered as carrying. as one is also permitted to walk on the rain during Shabbos.
See question 2262 regarding Toveling in a lake Shabbos morning by the cottage.
Rabbi A. Bartfeld as revised by Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu Shlit’a.