i think there's mods which does it. there may also be commands to destroy items in certain inventory slots, in which case imo the best option (so you don't accidently destroy something you want) is to set that slot to the last spot in your soulbag and include drain soul into the macro so it always destroys your last shard before getting a new one. but my macro knowledge is limited so you'll have to wait for someone else to actually write how to do this :P