I am looking for gourds (I think)

So I work with some Kumeyaay organizations in this side of the border, but in the valle I work with the Kumiai community there. They asked me for “Tu puedes conseguir bules ? Para hacer sonajas?” I understand these are gourds ti make rattles or maracas. I have seen a variety of these sonajas. But to confirm, am I looking for gourds? How does one dry them out? Cannot transport if there are seeds in them. So thoughts?