Impurities on clothing and furniture

Q: Before going to sleep, very small amount of mazi comes out. After waking up it is impossible to locate exactly which part of the garment has the impurity. What should be done in this case? Can salaah be offered without washing the garment since the mazi is not apparent?

Q: A white cloth, which was soiled with impurity, was washed after a long time. Before washing it, there was a stain in the place where the impurity was. After washing the cloth, the stains are still visible. Can one perform Salaah wearing these clothes?