Neochetina bruchii and other Neochetina are effective but in laboratory conditions only. Few years back the weed researchers declared that Parthenium can manage Water Hyacinth but later common people relaized that it was of academic interest only. The concerned researchers applied Parthenium extract on Water Hyacinth growing in small tub. It is not found feasible to apply Parthenium in bulk to manage this weed in ponds. Hence, after publishing the paper in reputed journal and receiving the award the researchers Never tried to move forward.
In Kharun river it was very easy to use the mechanical control measure as two sides were parallel. In this measure two tractors are run in both sides of river and between them chain is kept across the river. It removes Water Hyacinth within few hours. But due to lack of political will, BJP and Congress continued fighting over this issue and finally flood in rainy season washed the issue i.e. Water Hyacinth.
By the way please see this website selling furnitures prepared from Water Hyacinth. http://www.perfectpieces.co.nz/