Cantaloupe vines are "all boy"

[Gionanna Caboto]

I know it's normal for cucurbits to put out male flowers first to flag down the pollinators, but it's been almost 3 weeks now. How long should this bachelor party last?
Would it help if I took a paintbrush to them to mimic pollinators visiting? I have lots of solitary bees, but don't know if they're visiting these flowers.