I farmed langostines for export to Korea where they were ground down to go into cosmetics.

My product was live but I learned that the exporter just left them out in our tropical sun. That's how rice is dried. I don't think you have such a facility but I suppose that atmospheric exposure would do the trick. Without the flesh there shouldn't be too much of a 'pong' (Korea remember) so they could stand for a few days in the right wind. If you have waste wet steam you could accelerate the process with the odd prod from a lance. CAPEX might not be justified.

PS. 'tonnes' is already metric. ■