Answered by Shaykh Faraz Rabbani
a) My 3 year old daughter sometimes wets herself whilst sitting on the sofa, and on the carpet. Sometimes she will not say where on the carpet she has urinated, and we are not able to find it. It is also difficult to clean the upholstery on the sofa properly, so we allow the urine to dry.
Answer:
Walaikum assalam wa rahmatullah,
1. You can clean these in the way described in the answer below.
2. No, contact of a dry surface with dry filth does not lead to transfer of the filth unless any obvious traces (such as smell, color, or taste) of the filth appear on the former.
Wassalam,
Filth: A Soiled Carpet