I have doubts about cleanliness. A cat peed on my window, and we only cleaned it without purifying. Later, my maid used a wet cloth to clean that window and then used the same cloth on my whole home. What should I understand about the purity of my home?
Everything is Taahir for you unless and until you know for sure that it is Najis. Doubt about Najasah does not mean that the doubted item is Najis with out concrete evidence. If you have concrete evidence that a specific item is definitely Najis, then you can make it Taahir by pouring water in it.
Wassalam.