One of us would have a single shift in which she menstruated, and she might also become ritually impure while wearing it. Then, if she noticed a drop of blood on it, she would rub it off with her saliva.
حدثنا النفيلي حدثنا سفيان عن ابن أبي نجيح عن عطاء
قد كان يكون لإحدانا الدرع فيه تحيض قد تصيبها الجنابة ثم ترى فيه قطرة من دم فتقصعه بريقها
No references are available.
Its chain of transmission is daif. Bayhaqi (1/14) narrated it from the hadith of Abu Dawud through this route, and the hadith has corroborating narrations. Ibn Abu Najeeh is a mudallis, and he narrated using "an" (an ambiguous transmission formula).