And does it vary depending on the item?
I am genuinely interested I reckon my times would be-
Plate - 24 hours, I recently stopped buying crockery (clumsy DS) so we are now down to 5. This means that this is usually noticed when we are are dishing up tea.
Bowl/Small plate - 1-3 days. Again down to 5 and 4 respectively but will rarely use multiple bowls at the same time so would require me to want a bowl and the others being unwashed to noticed.
Cup - Never, I have apx 1000 cups.
Any item of cutlery - Never, none of it matches and I seem to collect it as if by magic.