My mil told me this with all my kids, I passed. The cons far outweigh the pros as there is only one pro that possibly your baby will sleep longer, baby also will be missing out on vital nutrition in order to sleep longer, not worth it.

Why? Is your son gaining weight? He's a month old and they don't sleep through the night. Cereal is just empty calories. No point in it unless he has reflux like my son did and even then it doesn't help much 🤷

Don't, there is absolutely no need. Unless your baby has reflux, trouble gaining weight and is recommended by a pediatrician.

Some people do it to "make baby more full" thinking it'll make them sleep longer it won't. Formula or breast milk has all the nutrition the baby needs.

Oh dear. Definitely a NO around here. Baby sleep is learned behavior not forced.

My thoughts are I would definitely pass. It's outdated advice, really not beneficial, and can actually cause harm.