Q. I have a friend that I met as a neighbor when we were kids and played together. Then as we grew up, he sadly became a terrible even criminal young man. By the grace of G-d and the help of friends, the greatest of miracles happened and he became a most serious and dedicated Baal Teshuva. He is now careful with keeping mitzvot properly and even to the smallest detail. He now, due to his prior misgivings, wants to wear a big Taalit Kattan, as some Chassidim wear on top of his clothing as a Shemira and protection from his prior misgivings.
He wants to know if it is a proper thing to do and if he has to take it off when he enters a bathroom.
A. On question 928 we wrote "There are many great benefits in wearing a Taalis Kattan, as the Torah mentions (Bamidbar 15: 39); “You will see it and remember all the mitzvos.” Tzitzis give us an anchor to the world of spirituality and thus protect us. Our sages say that one who fulfills this mitzva properly merits to have a wife and children. (Midrash Tanchuma, Ki Teitzei). He is also protected from sin, (Menachos 44a) and in that merit he is assured that he will see the face of the Shechina. (ibid. 43b.)"
Horav Shlomo Mille'rs Shlit'a opinion is that although as mentioned, the importance and benefits of wearing constantly a Taalis Katan are indeed very great, it is advisable to comply with the mitzva following the common ways of most religious people, and not engaging in excesses that most don't do.
The Rov added that one does not have to take off a large Taalis Kattan when he enters a bathroom, being similar to what others do when they wear a common Taalis Kattan. It is only when you wear the large Taalis that is dedicated mostly for the purpose of davening, that one has to take it off before entering a bathroom.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller and Horav Aharon Miller Shlit'a