Later in the game, when you find the TRADER, you'll be able to buy THUNDERSTONES. From wich you can build an item that will permanently destroy any item you put in it.
But as far as the actual recipe for items.. No, i don't think so.

Clean install.

Remove the evil taint brought on by the 'stone pickaxe'.

The only place known with fire hot enough to destroy such powerful items as the legendary Pick of Stone is in the land of Mordor where there is a volcano called Mt. Doom. If you can survive the dangerous journey and throw the artifact in the fires it will be destroyed. If you wish to destroy the knowledge of how to create such unspeakable evil, you may have to throw yourself in as well.

To the best of my knowledge recipes once learnt cannot be unlearnt. Items can be destroyed by throwing them at the entrance of a burial chamber. After throwing them at the entrance of a burial chamber they will disappear within a day or two, but I am not sure if this will work for your characters gear as it does for looted or harvested items.

PS: You might try posting your question in the bugs forum.

If you take gear that you don't want out on a boat into deep water you can throw it over board. If the water is deep enough you will never be able to auto gather it even if it doesn't eventually despawn.