Our Calabash gourds are pre-cured, scrapped and cleaned all the way, so need just a very good wash with boiling water to make the first maté!
Leave the moist overnight, no excess water to soak in, rinse well in the morning, WATER ONLY, and make sure it is it aways clean and drying overnight. The curing will happen naturally as you drink.
Expect spots and darker colors inside as the time pass, as long as it is dry it will be fine!
A gourd should last you many years!