A Mu'takif can let his head in the house for washing

Sahih al-Bukhari · Book 33 · Hadith 2046

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ، حَدَّثَنَا هِشَامٌ، أَخْبَرَنَا مَعْمَرٌ، عَنِ الزُّهْرِيِّ، عَنْ عُرْوَةَ، عَنْ عَائِشَةَ ـ رضى الله عنها ـ أَنَّهَا كَانَتْ تُرَجِّلُ النَّبِيَّ صلى الله عليه وسلم وَهِيَ حَائِضٌ وَهْوَ مُعْتَكِفٌ فِي الْمَسْجِدِ وَهْىَ فِي حُجْرَتِهَا، يُنَاوِلُهَا رَأْسَهُ‏.‏

Narrated `Urwa: Aisha during her menses used to comb and oil the hair of the Prophet (ﷺ) while he used to be in I`tikaf in the mosque. He would stretch out his head towards her while she was in her chamber.