With due respect to old age tradition of using Mahua flower, as a fish attractant, I beg to deffer that Mahua gives you an added advantage. Basically if you go on feeding fish any thing, it will get accustomed to the same and in my opinion, Mahua acts in the same capacity. Mahua will never work in a water where it has not been used extensively as a GB or HB.
I would rather concentrate on bait, which is rich in nutrients and the smell factor is as natural as possible.
To me fish will rather eat any thing, subject to an regular input of the same in the water body. The classical example being, you can only catch a good Mahseer, using Ragi, from South but if you try Ragi, for the same fish from the North, you will draw a blank. The bait used for Northern Mahseer is Atta and Turmeric
The second example is the Temple Mahseers of Bhakra and they attack Pakori with all the chilly and salt and what not
To me, if I want to experiment, using a natural smelling bait (From the fishes point of view), which is rich in nutrients and have some fat contents is the best way to go for our Carps.
PS. using alcohol in bait is another topic and the merits and disadvantages can be discussed separately.