| 2026-08-03 | Aid in making soap |
| 2026-03-30 | Caustic paint stripper |
| 2026-03-04 | Caustic cleaner |
| 2025-12-18 | NaOH |
| 2025-11-10 | Harsh cleaning agent |
| 2025-06-10 | Common name for NaOH |
| 2025-01-13 | Caustic drain cleaner |
| 2024-10-20 | "That's a ___!" (chemist's punny observation) |
| 2024-08-29 | Very basic cleaner |
| 2024-07-28 | Substance in a bagel-making "bath" |
| 2024-07-18 | Caustic cleaner |
| 2024-06-29 | Solution for many cleaning problems |
| 2024-05-14 | Caustic solution |
| 2024-05-10 | Wood ash + water |
| 2024-05-07 | Very basic stuff? |
| 2023-09-12 | Soapmaking ingredient |
| 2023-09-10 | Caustic cleaner |
| 2023-02-01 | Strong cleaner |
| 2022-11-18 | Compound used to make soft pretzels |
| 2022-10-27 | Solution to some chemistry problems? |
| 2022-08-02 | Caustic agent |
| 2022-07-18 | Ingredient in soapmaking |
| 2022-04-15 | Pipe cleaner |
| 2022-03-20 | It may be part of a solution |
| 2021-10-12 | NaOH, familiarly |
| 2021-09-26 | ___ soap |
| 2021-05-25 | Harsh cleaning agent |
| 2021-05-09 | Cleaning solution |
| 2021-04-05 | Caustic solution |
| 2021-03-07 | NaOH |
| 2021-02-10 | It's used in soapmaking |
| 2021-01-29 | Basic cleaner |
| 2020-10-22 | Strong base |
| 2020-09-28 | Corrosive cleaner |
| 2020-06-01 | Homophone of 24-Across |
| 2020-05-01 | Basic cleaner |
| 2020-03-29 | Drano component |
| 2019-01-28 | Chemical compound with the formula NaOH |
| 2018-11-14 | Ingredient in a drain declogger |
| 2018-09-18 | ___ soap |
| 2018-08-01 | Soapmaker's supply |
| 2018-05-28 | Powerful cleaner |
| 2018-02-08 | Burn cause |
| 2017-10-28 | NaOH |
| 2017-10-15 | Caustic soda |
| 2017-06-28 | Chemical in Drano |
| 2017-01-02 | Caustic agent |
| 2016-01-15 | Strong base |
| 2016-01-13 | Corrosive stuff |
| 2016-01-10 | Oven cleaner ingredient |
| 2015-05-13 | Caustic substance |
| 2015-04-20 | Caustic compound |
| 2015-03-16 | Potent cleaning solution |
| 2015-02-05 | Pipe cleaner |
| 2015-01-18 | Solution for some housework |
| 2014-09-24 | Caustic material |
| 2014-08-22 | It's KOH, chemically |
| 2013-11-03 | Grease dissolver |
| 2013-10-27 | Cleaning solution |
| 2013-10-04 | Basic solution |
| 2013-04-11 | Oven cleaner component |
| 2013-01-05 | Cleaning agent |
| 2012-06-18 | Soapmaking stuff |
| 2012-05-21 | Chemical in drain cleaners |
| 2012-03-20 | Soapmaker's supply |
| 2012-02-05 | Caustic soda |
| 2012-01-17 | Cleaning substance |
| 2011-11-22 | Caustic substance |
| 2011-11-19 | Burning stuff |
| 2011-06-22 | More common name for caustic soda |
| 2011-04-24 | Burn cause |
| 2011-01-06 | Caustic soda |
| 2010-09-27 | Soapmaker's need |
| 2010-05-24 | Drano ingredient |
| 2010-05-06 | A corrosive |
| 2010-02-08 | Caustic drain opener |
| 2009-09-23 | Caustic substance |
| 2009-08-06 | Cause of some skin burns |
| 2009-08-03 | Soapmaker's supply |
| 2009-06-03 | Chemical in Drano |
| 2009-05-17 | NaOH |
| 2009-04-10 | Burning substance |
| 2008-12-07 | Burn cause |
| 2008-08-12 | Chemical in Drano |
| 2008-08-05 | Caustic cleansing agent |
| 2007-08-26 | Oven cleaner ingredient |
| 2007-08-12 | Alkali in cleansers |
| 2007-06-19 | Caustic alkali |
| 2006-12-21 | Drain unclogger |
| 2006-10-22 | Heavy-duty cleanser |
| 2006-05-21 | Burn cause |
| 2006-01-10 | Soap ingredient |
| 2005-09-26 | Strong alkaline |
| 2005-09-11 | Clog remover |
| 2005-09-04 | Soapmaker's need |
| 2005-06-21 | Sodium hydroxide |
| 2005-05-01 | Strong cleanser |
| 2004-07-22 | Potassium hydroxide |
| 2004-03-29 | Caustic substance |
| 2004-03-01 | Caustic substance |
| 2003-09-21 | Caustic chemical |
| 2003-04-26 | Ingredient in some cakes |
| 2003-02-16 | It makes soap strong |
| 2003-01-06 | Caustic chemical |
| 2002-12-16 | Basic cleaner |
| 2002-09-08 | Soap-making ingredient |
| 2002-08-06 | Soapmaking need |
| 2002-07-07 | Strong cleaner |
| 2001-12-25 | Drain cleaner ingredient |
| 2001-09-27 | Tough cleaner |
| 2001-09-02 | Strong cleanser |
| 2001-08-14 | NaOH or KOH |
| 2001-07-17 | Strong alkali |
| 2001-07-08 | Eye burner |
| 2001-01-01 | Strong cleaner |
| 2000-09-12 | Soapmaking need |
| 2000-08-27 | Lixivium |
| 2000-07-17 | Common name for sodium hydroxide |
| 2000-05-05 | Leaching product |
| 2000-03-11 | Potassium hydroxide, e.g. |
| 1999-06-20 | Caustic cleanser |
| 1999-06-13 | Bleaching solution |
| 1998-12-05 | Leaching product |
| 1998-09-07 | Caustic substance |
| 1998-08-12 | Soap solution |
| 1998-07-30 | Bleaching agent |
| 1998-05-08 | Lixivium |
| 1998-05-04 | Burning substance |
| 1997-12-23 | High-pH substance |
| 1997-10-20 | Soapmaker's solution |
| 1997-06-20 | Heavy-duty cleanser |
| 1996-11-06 | Potash |
| 1996-07-21 | Potassium hydroxide |
| 1996-06-02 | Potash |
| 1996-05-06 | Old cleaning substance |
| 1996-02-20 | Liquid in drums |
| 1995-03-03 | Drain opener ingredient |
| 1995-01-03 | Drain cleaner |
| 1994-11-28 | Soap ingredient |
| 1994-09-22 | Drain cleaner ingredient |
| 1994-09-14 | Caustic agent |
| 1994-05-11 | Caustic |
| 1994-04-16 | Familiar solution? |
| 1994-02-20 | Burn cause, perhaps |