Go for the real thing!
Nearly everyone takes their holy baths in Har ki Paudi. It seems too man-made for me. Why not take your 'cleansing' in the more real Ganga at nearby Neel Dhara (or Neel Jheel, I forget). It's much wider, cleaner, and above all, less crowded! It will be far more apt. It's not as deep as people make it out to be, nor are the currents that strong. Yes, it's deeper with more pressure than Har ki Paudi but (that's the point and) so very doable!! It will just feel like the real thing.

GARDENS AT CHEETAL
Banks of the Ganges
Evening aarti on the Ganges
Pilgrims arriving from all over the place