Mangos are a major export industry here and the majority of fruit is subjected to chemical treatment. But some organic growers were exporting to Germany and they used heat treatment on the fruit. The govt. ag. people have always been against it and were throwing up obstacles. Finally some of the people I knew who were doing it gave up the business and I don't know if anyone else has continued. You need to know what you're doing with heat treatment because the process can set off physiological processes and you end up "shooting yourself in the foot". But as I mentioned above, if the Anthracnose gets in early when the fruit is small it can stay as a latent infection and come out later no matter the treatment. Spores don't just suddenly turn up when the fruit has matured, they're around all the time.