Is it ruled that ritual impurity transfers to the sofa, clothing lint, and the rest of the house merely by doubt, or not?

The treatment for obsessive-compulsive disorder (waswas) is to completely disregard it. Sprinkling water on madhy (pre-seminal fluid) is sufficient to purify it. A small amount of madhy is excused by many jurists. In fact, it is permissible for someone suffering from waswas to adopt the ruling of excusing small amounts of impurities entirely, and not to pay attention to doubts about the transfer of impurity. It is recommended to consistently make supplication (dua) and to consult a psychiatrist.