The sixth section should have been thrown out by Sankaracharya. It has obnoxious passages that are contrary to morality. The obnoxious passages tell us about ancient customs and should not be treated as Shruti.
Discourses on morality made with the aid of an intelligence that is
derived from the true letter and the spirit of the scriptures, are
worthy of praise and not those which are made with the help of
anything else. Even the words heard from an ignorant person, if in
themselves they be fraught with sense, come to be regarded as pious
and wise. In days of old, Usanas said unto the Daityas this truth,
which should remove all doubts, that scriptures are no scriptures if
they cannot stand the test of reason.
Mahabharata Santi Parva Section CXLII
One should realize that Vedic infallibility does not imply the acceptance of every word in it.
The appeal to the infallibility of the Vedic injunction is
misconceived. The infallibility in question refers only to the unseen
forces or apurva, and is admissible only in regards to matters not
confined to the sphere of direct perceptions, etc ... Even a hundred
statements of sruti to the effect that fire is cold and non-luminous
won't prove valid. If it does make such a statement, its import will
have to be interpreted differently. Otherwise, validity won't attach
to it. Nothing in conflict with the means of valid cognition or with
its own statements may be imputed to sruti.
REF: Srimad Bhagavad Gita Bhasya of Sri Sankaracarya translation by Dr. A. G. Krishna Warrier, p. 629.
Moreover neither Shruti, nor Smriti, nor ancient custom and tradition can override one's conscience.
Bhishma said, ‘He is said to be conversant with duty who knows duty as
depending on four foundations.’
[four foundations, i.e., as laid down in the Vedas; as laid down in the Smritis; as sanctioned by ancient usage and customs; and as approved by the heart or one’s own conscience.]
Mahabharata, Santi Parva, Section CXXXII