Historical clue formulations

• Slicker — 2021-05-17
• More slick — 2021-03-24
• More greasy — 2009-09-28
• More smarmy — 2007-08-09
• More unctuous — 2003-05-07
• Superior in lubricity — 2000-10-15
• More unctuous — 1999-06-16
• More smooth — 1998-05-17
• More slick — 1997-11-19
• Slicker — 1993-12-12