Is it necessary to wash the clothes and vessels of one who enters Islam?
Question

                Is it necessary to wash the clothes and vessels of one who embraces Islam?.
Praise be to Allah.
    That is not necessary, because the more correct view is that 
    the najaasah of non-Muslims is intangible, not tangible, because the Prophet 
     (peace and blessings of Allaah be upon him) and his companions did 
    wudoo’ after drinking from the leather vessel of a mushrik woman, and 
    because Allaah has permitted us to marry the women of the People of the Book 
    (i.e., Jewish and Christian women), which implies touching them. And because 
    Allaah has permitted the food of those to whom the Book was given, which 
    also usually implies that they must have touched the food. 

    Based on that, if a man becomes Muslim he does not have to 
    wash his clothes, bedding and so on, unless he is certain that some najaasah 
    (impurity) got onto them and they have not been purified from it. End 
    quote. 

    Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him).