Translation:Shulchan Aruch/Orach Chaim/21
21: The Proper Course of Action Regarding Severed Fringes and Old Shawls.
1 The strings of the tzitzit that were severed may be thrown into the garbage, because it is a commandment that is not holy for its own sake. However, as long as as they are attached to a tallit, it is forbidden to use them for something else like to bind anything with them and so forth, because this would be to scorn the mitzvah. [And there are those who say that even after they have been severed, one should not treat them in a scornful manner to throw them into a disgusting place, but that they do not require ritual burial [Kol Bo, Laws of Shabbat]. And there are those who are punctilious to ritually bury them, and the one who is stringent and careful regarding mitzvot, a blessing shall come upon him [Maharil, Laws of Tzitzit] [And see below, section 664 paragraph 8-9].
2 Garments used for the commandment, that wore out, a person separates himself from them, and one is not permitted to wipe himself with them, and not to designate them for a disgusting use, rather he throws them away, and they disintegrate.
3 It is permitted to enter a bathroom with tzitzit. Gloss: And of course to sleep in them is permitted. And there are those that wrote that it is the custom to not sleep in a tallit that has tzitzit on it, also, not to give it to a heathen cleaner to clean. And everything is so that commandments shouldn't be despised upon him. However, the custom is to be lenient to sleep in them [Kol Bo].
4 There should be caution, when a man puts on a tallit that he shouldn't drag his tzitziot.