No. I wouldn't throw them away, just chalk it up to a learning experience and continue to flower them. I'd rinse them, folks say it doesn't do much good though.
How long can you use neem oil into flowering? does it have any effect when it is sprayed onto the forming buds? obviously I wouldnt use it the last week at least but can you use it until then?
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You implied they were photoperiod plants. If so, you could revert then re-initiate flowering again later, and cut all the buds off. It takes at least a couple months, maybe 4 if you want a lot of new vegetative growth. It would allow you to pick all the buds off, trim it up, develop some new leaves and stalks, then flower.