What is the ruling on the impurity that has affected the house tiles due to a clogged toilet, and how can it be purified if the cleaning method used is insufficient, and what are the implications of its spread throughout the house?

Filth (najāsa) is not transferred by mere doubt. The default state of things is purity unless their contamination is certain. Many scholars hold that filth is not transferred from a contaminated object to a pure one if either of them is wet or moist. A person suffering from religious scrupulosity (waswās) may adopt the easier of the opinions to alleviate their burden.