There are a number of different methods to dry gourds. Gourds have been drying by themselves for eons and have been doing just fine. In fact, I believe gourds will cure faster if left right on the vine until dry.
Patience is a must. They will gradually become lighter and lighter. They will be fully dry when extremely light weight and the seeds inside rattle when the gourd is shaken.
Gourds need air to properly dry. Lots of air.
Gourds are probably 90% water and it could take them 3 – 6 months to fully dry.
Curing gourds quite often get a mold on the outside of their skins. It’s just a part of the drying process.
Clean dried gourds in warm water with a copper pot scrubber. No need to use bleach. Soak for about 20 minutes, then scrub off the outer layer of dried mold and skin. Let dry overnight, then you are ready to craft. You can cut, drill, paint and stain a gourd just like wood.