Sex tourism works too. Look how it transformed Indonesia, Thailand, Philippines & Vietnam.
Sex tourism is not just about female prostitution. Sri Lankan males have a huge appeal among women in European countries. (the whole beach boy cliché, but it's true) If you have a moderate physique and speak good English, try having a white girl as just a friend. It's virtually impossible.
One budding section is middle aged couples who come here to satisfy cuckold fantasies. There's a huge demand for skinny, dark skinned guys aged 18-22 or so.
Sri Lanka is the best place in all of asia for Gay tourism. There's a saying among foreigners that if you need a boy, there's no better place than Sri Lanka.
Of course, as with anything sex related, consent and willingness is key to all of this. We should properly regulate the whole thing, leaving very little to exploitation attempts. If this is done properly, we can really make this country a paradise in the Indian ocean.