Two things.
First, a closer look at the Balearic slingers and their history (especially after the Roman empire), both general information about how they used the sling on their hometurf, why they were sought after mercenaries and if any weird little differences existed between the slingers of different islands. Anything really.
I know for a fact that Rome got their slingers from Majorca and Carthage from Menorca. The Majorcan slingers made split pouch slings and the Menorcan ones had straps of leather between the two strands (at least when in Carthaginian service). Had someone tell me that slinging was never prevalent on Ibiza (the term 'Gymnesian slingers' would be more accurate
) and that slinging had died out by modern times all over the Balearic (less sure about that one).
Second, more far fetched, but if you are going to bring up the Balearic islands again and again and again (might happen) you could after a couple dozen episodes make a special simply talking about every aspect of the Balearic islands, like its history, modern culture, interesting sightseeing points and slinging ranges . That might lure a couple of people to visit the island during the yearly slinging event and it has more than enough interesting sights to already be of note for tourists.