When my Daughter was born I was the one who dealt with her at night time for 4 weeks after our confinement nanny left. To get her to sleep I would swaddle her, hold her on her side in my arms and rock her gently while saying “shushhhhhhhhh in her ear till she calmed down” she would fall asleep in about 2 minutes. Then I would place her in the cot slowly and pat her bum for 5 minutes. Then she would sleep for 3-4 hours till next feed.
I had never heard of the 5 S’s but the similar things I did they do work.