What is the ruling on praying in the mosque while wearing a sock that has been touched by the sweat of an unclean foot — with the possibility that the substance of the impurity has been removed — according to the Maliki school of thought, and is re-performing the prayer obligatory for someone who did so out of ignorance of the ruling?

The whisperings [waswasa] have reached a great extent for you, so you must struggle against them and not succumb to them. For succumbing to whisperings leads to great evil. Build upon the original principle, which is the purity of things, and do not rule them impure except with certain conviction that you could swear by. You were mistaken in abandoning prayer in the mosque, and this is from the Devil's cunning. So, seek refuge with Allah and maintain congregational prayer in the mosque. Be certain that your socks are pure and you are permitted to enter the mosque with them and step on any carpet. You must also advise your brother to maintain his prayers.