This goal has the following fine print specified by peppertoni:
An item can be counted as progress when it has left the house or is committed to leaving the house (e.g. listed in an auction, in a rubbish bag).
Things that belong in pairs or sets shall be counted as a single item. So, a pair of socks would be one item. An odd sock would also be one item.
Duplicates of the same item may be counted as separate items, provided they are not dependent on each other to fulfil their function. So, three pairs of socks will count as three items. This rule may be modified if the challenge is deemed too leisurely.
Items must have been kept, rather than just having missed the rubbish.
Giving an item away to somebody in the same household does not count, unless they have a legitimate use for the item and ownership is transferred.
Facilitating the removal of a household item can count, even if the item is not explicitly owned by the individual.