I have seen a person who has Ketu in the twelfth house and I must say he was one of the meanest person I have seen so far. But we know this does not say everybody must be mean whoever has Ketu in the twelfth house. We already know every planet has two aspects good and bad. On the negative side Ketu gives severe complexes, psychological abnormalities, anger, fanaticism, explosiveness, violence, unconventionality, amorality etc. etc.
On the positive side it gives universality, impressionability,idealism, intuition, compassion, spirituality, self sacrifice, subtleness, detachment and finally salvation. Now how Ketu will behave in the twelfth house for that we should take into consideration the whole of the horoscope.
For example the person I am talking about had the aspect of eighth lord Saturn on the fifth house from the house of gains. The lord of the fifth house was in the sixth house with Rahu. The ninth lord Jupiter was in debilitation in the seventh house that also in paapkartari yoga. The ninth house was receiving the asepct of Mars from the sixth house Saggi. The ascendant lord Moon was in the fourth house in kemadruma yoga. The ascendant was receiving the aspect of eighth lord Saturn. Last but not the least the tenth house of Karma was also afflicted because the lord Mars was in the sixth house in nodal axis without any beneficial aspects
Now all these combination will give a picture of highly greedy, immoralistic and cunning man. Now if this man has Ketu in the twelfth house, its meaning must change because there is no support from anywhere. It must not be moksha karak but must increase all the maleficity of the twelfth house which we all know that it is the house of Bhoga or physical enjoyment also.
So, in that case after scrutinizing everything we can accept that Bhrigu is right when he says that Ketu from the Atmakarak in the twelfth house goes to hell. But if fifth and ninth house are strong and recieving the aspect of strong benefics, the tenth house of karma has the influence of benefics then of course the meaning must change and we can conclude that Ketu in the twelfth house is pointing towards severe detachment from every worldly enjoyment so it can be termed as Moksha Karak.
Now I will move a step away. What would happen if in spite of having all the benefic combinations the person has afflicted Ketu in the twelfth house. For me it depends which planet is afflicting and from which house he belongs to. Like imagine that Ketu is getting afflicted by second lord Mars now in this case the immense struggle will be there between materialism and spirituality. The person may trap in the dichotomy of being spiritual and materialistic. He may want to tread upon the path of spirituality more than sincerely but deep inside he has material desires as well. Now whether he will come out of it and may get enlightment this depends which instinct is taking edge over other and then again the whole horoscope will come into play.