Praise be to Allah.
There is nothing wrong with the pilgrim in ihram bathing or washing himself. It is proven that the Prophet (blessings and peace of Allah be upon him) bathed when he was in ihram.
With regard to shampoo, it seems that its scent is not perfume; rather it is a scent and fragrance that is well liked, as in the case of mint and other fragrant leaves. What matters is that whatever is perfume is not permissible for the pilgrim in ihram to use. End quote.