Unwanted souvenir is a common reason. The generation that went to most wars are now passing on and the relatives upon finding said prize grenade just want rid with minimum fuss. Not realising that this removal is exactly what we do, they however in ignorance carry out a 'shallow water dump' in the local canal. Which is illegal.

As for the term legally deac'd that does not exist. To inert any ammunition, (even SAA) is classed as the illegal modification of ammunition and can lead to imprisonment. There are very few people who can state something is inert in the Uk likewise in most nations. And all here are Military or Gov't and fully trained to do so. Anyone else stating 'Inert' is just blowing hot air as they are unable to state that. Yes I see it regularly and on occasion have taken great pleasure when finding residual explosives in having the so called self appointed expert charged accordingly!