I think there has to be some kind of honor system, and other people just look away... because you know... you don't want to be alone in the Ways... haha so it's not like you can be like oh yeah go on ahead I will catch up...
So if we're basing the WoT world on 18th century Europe, it likely would have been.....a bit less of a closeted activity. My bet (based on historical evidence) would be most likely strategically placed buttoned flaps in travel clothing and/or likely a specific weave opening an Otherspace void (a la the Otherspace pockets from Diane Duane's Young Wizards series) for doing one's business. 😉