I too was faced this problem when I left Maharaji - I had had such sweet experiences, watching the sunlight on the sewer, as you put it, and feeling gratitude for life etc.
If Maharaji is a fraud, do these beautiful experiences that we had when we were with him, or when practising the Knowledge, mean that they are or were nothing? And in leaving Maharaji did I have to leave all the dreams and hopes and love of life that gave me meaning, simply because I had them under his tutelage?
I spent about a year completely absorbed in these questions, and trying to sort it all out in my mind.
I believe two things:
1) Human beings can have a wide range of experiences - certainly more than they think they can;
2) Human beings have an even greater capacity to interpret and explain their experiences, almost with no limit.
Put these two facts together, and you have more than enough to explain premies having cosmic experiences, which they interpret as due to Maharaji and his grace.
I certainly had very profound experiences around Maharaji, which at the time I firmly believed was because of him, or my practice of 'his' Knowledge. However, I have had similar experiences both before and since (particularly since), and they were clearly nothing to do with Maharaji.
So I believe that the conditions (large crowds focused on him, my expectancy, my hope) enabled out of the ordinary experiences to happen; it was my interpretation that made them experiences 'of Maharaji'. One thing I am sure of: it was not Maharaji consciously doing anything that was their cause!
Many, many other groups or belief systems allow for a similar phenomenon. An example at random is the healing at Lourdes, where the faithful go to get cured. The belief is that the Virgin Mary (through her lieutenant, Bernadette Soubirous) will cure you if you go there and believe that you will. In fact, people do get healed. Is it due to Mary (dead 2000 years) or Bernadette (dead 130 years) floating around and making it happen? I don't think so, but then again, if I really get healed, who cares?
Same with my experiences around Maharaji - some of them I remember clearly with great joy even now, and they had a deep effect on me. Did Maharaji cause them? No, but I don't care - the experiences themselves were the thing.
I am happy to have found that it is possible to throw away the bath water without throwing away the baby. The process of becoming intimate with my life and with my consciousness took a little dive after I left Maharaji, but is now back on track stronger and more profound than ever.
My life is a continuous thread of being - in the final analysis, I cannot separate it into episodes - 'before Maharaji', 'with Maharaji', 'now I have left Maharaji' etc.