Can you clarify on the difference? Also, right now I stick the loose leaves into a tea sack and let that steep in my mug--would that accomplish the same functi

Can you clarify on the difference? Also, right now I stick the loose leaves into a tea sack and let that steep in my mug--would that accomplish the same function as the gourd? My gut says there would be no material difference in taste between my current method and the gourd, and it would be an unnecessary expense, but if there's something I'm missing as to what it does to change the flavor/experience I'd love to know more.