Adiyen’s husband wears Thiruman kappu the whole day and sometimes washes it before going to bed, should it remain even while sleeping, please clarify.

It is inappropriate to wash the Thiruman kappu before going to sleep. Swami Desikan has stated that one should be with Thiruman kappu even while sleeping. We should wash that during the morning bath so that we can apply fresh Thiruman kappu for the day.