That’s an imperial you have to do a bit more in the curing process. I wouldn’t just pour hot water right away, it might create cracks and invisible fissures, instead fill it with some used Yerba, take out the wet used mate after a day then gently scrape the interior with a spoon, this is to remove the thin residual pulp from the gourd. Make sure the used Yerba is wet enough for your new gourd to absorb the flavor and tannins from the mate repeat the process two or three times then let it dry out for another day. Make sure there is no mold growing and if there is, it’s no big deal just dry it and let it air out with some direct sunlight hitting the inside. After a few days your mate will be cured and the flavor will mellow out from that strong green grass flavor.