I’ve spent so much time trying to find Loop replacement and somehow stumbled upon this one. You can even use exports from Loop with some script I found on reddit.
It works ok, but I would love official Loop app for ios.
I think it took me less than two weeks, two sessions per day. You first need to listen to it enough times so every step becomes fully familiar - this was, at least for me, pretty important because you don't have to think and anticipate what is coming next.
Sleep time didn't reduce, I still like to go for 8 hours of sleep whenever I can - but if I sleep less or get tired NSDR is a secure "fix".
One more important tip is to do one session just when you go to bed. Use it to fall asleep or to get sleepy. This way the sessions during the day get better.
Also, do it without headphones if possible, and with low enough volume just to hear instructions.
Yoga Nidra and NSDR done sometime after the noon made a huge impact on my energy levels.
After ~20min session I feel like a new person, ready to tackle the rest of the day.
Of course, it gets better the more you do it (today I can go to that near sleep state in just a minute or two).