I wouldn't do it on demand - I would do it when convenient for you.
As @NatJ said - do a morning and afternoon 'serving' and then ignore their screams the rest of the time.
I think you are overthinking the 'teaching' aspect to this. They will know that you are the source of all goodies and will...
My grown hens will murder for wet mash too. Long term it is good they like it as it is a convenient way to administer any supplements they might need over time.
When wet isn’t provided they will eat the dry if it is available.
I personally don’t think you should worry about them screaming at...