How long would you shake your baby (< 10months) in the sarong/ yao-lan, to encourage her to sleep?

I personally not recommended. Shake the baby will interrupt the baby’s brains development. You can put the baby against you and gently rock the baby with your body not just your arms. The baby will feel more safe and secure that way. Also will sleep peacefully. When your baby sleep put the baby on their bed. No light, no sound, and no interruptions. You will have a happy baby not crying for carrying all the time.