My two cents on CHR is that its effectiveness is based on how high it is relative to mob CHR. Hence a number of around 100 or so is plenty sufficient for most things you encounter in the game, and for some of the beefier HNMs you may want to get more towards the 110-120 range (which when all is said and done, means "use the same gear, actually eat food for a change, and etude yourself" which can amount to a CHR difference of 30 or so).
I happen to like AF+1 over Minstrel's Coat for debuffing not for potential debuff effectiveness, but so I don't have to delegate some *other* slots to CHR instead, and can wear more interesting things there (such as Tamas Ring or Loquacious Earring). For a pure debuffing build, ideal (not necessarily practical) would probably be something like:
- (Post-update) 8 Wind, 8 Singing merits (16 wind, 16 singing)
--- CHR merits if feeling particularly overkill, but lolCHRmerits
- Appropriate HQ elemental staff
- Gjallarhorn (4 CHR, 10 wind, 10 singing)
- Marduk's Tiara (3 CHR, 7 singing)
- Wind Torque (7 wind)
- Singing Earring (3 singing)
- Musical Earring (5 wind)
- Minstrel's Coat (3 wind)
- Choral Cuffs +1 (7 CHR, 10 singing)
- Heavens Ring/+1/Light Ring x2 (5 CHR each)
- Astute Cape (5 singing)
- Gleeman's Belt (6 CHR)
- Choral Cannions +1 (8 wind)
- Goliard Clogs (4 CHR, 2 macc)
Pre-food/buff total (not counting occasional 2 CHR on Apollo/Pluto Staff): +34 CHR (= 104 or 96 depending on race), +49 wind (= 274), +51 singing (= 276), +2 macc (= who knows)
However, that is *way* overkill for sticking debuffs on practically anything in the game you'd come across (and anything that's resistant even so, is probably just plain gonna be resistant no matter what, and you might as well free up some other slots for other stuff). Which means you may be better served with somewhat less of an ideal debuffing setup, and have something instead that has, say, auto-refresh and more -enmity and more max MP.
Either way, Osode is not something to stand around in for HNMs. It has no auto-refresh and it has no -enmity. Throw it on if you pull hate and are getting smacked, otherwise it's kinda pointless. (Protip: +/- enmity also affects how fast you bleed enmity while doing nothing, so don't just limit it to macroing in to hate-generating actions.)