If you bury them your just doing what the people told you to do at the tip at the end of the day if that rubbish goes to land fill. I would ring the environmental team at your local council they should be able to tell you what to do.
If your household waste goes for incineration you could put them in there maybe.
"You don't stop gardening because you get old, you get old because you stop gardening." - The Hampshire Hog
Our dustbin waste is incinerated locally at a an eco-plant (high gas capture technology etc). I should think that should be safe enough for my local users to destroy the pellets.
Posts
If your household waste goes for incineration you could put them in there maybe.
"You don't stop gardening because you get old, you get old because you stop gardening." - The Hampshire Hog
https://www.gov.uk/government/news/restrictions-on-the-use-of-metaldehyde-to-protect-wildlife