Maebee - I have done this. I found it worked fantastically with my LO.
I used put her down, swaddle around her, but allowing her to move arms out later if she wanted. shh, pat her/rub her arms through swaddle, with one hand gently on her chest, tell her I love her. If she became upset, pick her up, straight back down, whether crying or not, reswaddle her. If she sits up/stands up, pick back up/re-swaddle. What I found is that after a few minutes her angry cry became a cooing cry, then I knew she would likely sleep. Now, I think because she has learnt to put herself to sllep, she can sometimes be left before she is asleep. Sonetimes she cries as I leave, usually goes to sleep within 5 mins if I leave her, mostly sleepy cry. Or she will talk to her bear for a bit and then go to sleep. If she gets upset at all, I go straight back in and do pu/pd with her until she settles again. I sort of adapted it to meet her cues, which seem to change gradually over time. Sometimes, not often, but it has happened, she actually gets more distressed if I stay. One time I went out for a break as it just was not working (I was confused as it always worked before) and within minutes of going, she was asleep! Sometimes also, she wants to move to her side, and I let her, as long as she keeps still there, if she moves arms about, tries to get up, I pick her back up and put her back down on back.
Last night
7:45pm - 8:30pm pu/pd
8:45pm - 10pm - woken by phone! No BF, pu/pd went to sleep about 10:30pm, woke at 2:30am. BF, back to sleep until 7:30am. Probably would have slept from 8:30pm to 2:30 if not woken up.
Night before better 7:30pm - 1:30am - 2:30am - 7:08am!!! yeah
Sorry for long post, just think this is great, for my LO at least, its more fluid and natural for her, and she knows she can do it on her own now, but I am there if she struggles
Godd luck. I hope it works for you.