Historical clue formulations

• They're grated outdoors — 2025-04-26
• Sink holes — 2021-02-21
• Spots for snakes — 2020-04-18
• Empties, as a bathtub — 2014-11-10
• Flows out — 2013-05-12
• Pulls the plug on — 2001-06-12
• Sink outlets — 2000-07-10
• Saps — 1994-10-15