Child specialist will not recommend in using sarong because it is not good for baby's spine. Yeah my eldest son's child specialist always remind the dangerous of using sarong. My eldest son stop using sarong when he's about a year old, he was exclusive breastfeeding until he reached 3 and half years old.
The above picture of my toddler having his nap in sarong, you can see his sleeping in comfort. Once he's sleep we have more time to do house chores.
One of my friends told me that her baby left for babysitter to care, she spotted her baby's in sarong but her sarong's covered/surrounded with napkins. It's like surrounding it making it pitch dark inside. It's no good too because you don't know if baby's having enough air to breath or not.