Trawling through recent sessions, I found these:
This is already in items.txt, but with a trailing spaceUnexpected plural of 'one-day ticket to Dinseylandfill' found: one-day tickets to Dinseylandfill
Unexpected plural of 'iceberg lettuce' found: heads of iceberg lettuce
Unexpected plural of 'shoulder-warming lotion' found: bottles of shoulder-warming lotion
Unexpected plural of 'bucket of fish juice' found: buckets of fish juice
Unexpected plural of 'flashy pirate dreadlocks' found: wads of flashy pirate dreadlocks
Unexpected plural of 'funky eyepatch' found: funky eyepatches
Unexpected plural of 'Leonard's glasses' found: pairs of Leonard's glasses
Unexpected plural of 'actual tapas' found: lids of actual tapas
Unexpected plural of 'plate of Heimz Fortified Kidney Beans' found: plates of Heimz Fortified Kidney Beans
Unexpected plural of 'plate of Mixed Garbanzos and Chickpeas' found: plates of Mixed Garbanzos and Chickpeas
Unexpected plural of 'plate of Tesla's Electroplated Beans' found: plates of Tesla's Electroplated Beans
Unexpected plural of 'lion musk' found: vials of lion musk
items.txt has it as bottles instead of cupsUnexpected plural of 'lavawater' found: cups of lavawater
Unexpected plural of 'ice wine' found: bottles of ice wine
Unexpected plural of 'jangly spurs' found: pairs of jangly spurs
Unexpected plural of 'bottle of Amontillado' found: bottles of Amontillado
The items.txt entry has an 's' at the endUnexpected plural of 'high-grade explosives' found: vials of high-grade explosive
Unexpected plural of 'bat-o-mite' found: sticks of bat-o-mite
Unexpected plural of 'Jokester makeup' found: sets of Jokester makeup