Simple fix to a baby ear pressure: Valsalva Maneuver. You do it every time you hold your nose and blow to release pressure in your ears. A quick hold and release of an infant’s/child’s nose can clear their pressure jsut as well. It might take several tries to coordinate their blowing out and you holding their nose for them, but it works just the same. For children that can safely chew gum, gun chewing can also help.
A Valsalva Maneuver? Do you even know what that is? I highly doubt it because that’s a dangerous thing you’re talking about. And you’re advocating using it on a baby? You have some sort of malfunction.