One can wear Thiruman and Srichooranam on the forehead during the 10-day paternal relative’s death impurity. However, for the Srichooranam, you must wear only Srichooranam that has not undergone consecration (Pratishtai), that is, Srichooranam bought from a shop. There is a ritual called Sri Choorna Pratishtai; you should not wear Srichooranam that has undergone that consecration during times of ritual impurity. Sandhyavandanam and Gayatri Japam must definitely be performed. It should be performed without Anganyasam and Karanyasam. Impurity (Theettu) itself means lack of cleanliness or unsanitary conditions. Perumal’s inner vessels must always remain pure. Impurity should not mix with them. Impurity can be introduced in many ways, such as picking things up without washing hands. In Sanskrit, impurity is called Asaucham. Since we ourselves are in a state of Asaucham during that time, if we touch those vessels, they will also become impure, which is why we say they should not be touched.