yeah at least in my experience you kinda have to just not use shampoo for a month before the scalp realizes and stops pumping out grease, after that period the need for shampoo is basically nil

as for the “less” bit, i more meant using a smaller amount every time, in my experience just a little goes a long way and i think the thing that causes the scalp to overreact with all the grease is that you periodically nuke all the oils completely, if you leave at least a little oil the scalp will probably calm down.