I used boiling water on the child's minor burn
Are you serious! Why would you pour boiling water on a child?
I read that boiling water will kill germs.
That's textbook child abuse. You could be in jail right now for burning your child again. Take your kid immediately to the hospital and have them treated by a doctor.
He's not hurt too badly and I didn't use lye or cement like the internet says.
You are spending too much time reading crackpot medical theories and this time you ending up burning your kid because of it and it's not correct. Leave the medical care to the professionals.