When I hung gourds, the birds used them.
Unfortunately, those gourds never lasted as long as the wood bird houses.
Sorry to hear that it took so long for them to dry...
At my house, i set them on a rack so the air could circulate... The difficult part was in removing the seeds.
I tried cutting of some them open, removing the seed and pulp, adding beans, and gluing them back together as murakas or rattles... But even that wasn't very long lasting.
Any more... I just leave the gourds as decorations here and there through the garden... for people to ask me... What's that?