Honestly, the only reason I would seriously think of going back would be if I found a girl irresistible and I had to have her. Even then it would be to coerce her into marriage, wait a couple of years (or months), teach her about TTATT, then fade with her again into the sunset.
Of course, the odds of this are slim to nil. but that would be the only reason I would enter a KH after a successful fade. Otherwise it would be nothing but torture. also you run the risk of the girl being a stout jw and non-changeable...hence my plan would be crap and a waste of 3 years.