If you're appealing to realism, then I'd remove the str/dex maledictions altogether and do something like this:

Big kot stays the same, nuking your off hand entirely. Little kot changes to an effect sort of like grease. If you're dual-wielding a weapon, then every time an attack from your off hand is parried or blocked there's a decent chance that you drop your offhand weapon. If you're using a shield in your off hand, then every time you block an attack there's a decent chance that you drop it.

If your dual wield is an instrument or held item...umm...not sure what to do there. This change would make Kot less effective against people like 2h paladins, bards, and invokers.

Both varieties of kans add an effect like symphonic echos, where you randomly miss melee attacks and any skills that involve using your arms. Skills that don't involve the use of your arms (e.g. dirt kick) would not be affected. There would be no "slow" effect from big kans, just an exaggerated version of the overall kans effect.

These changes would also make it so nobody could "prepare" for or negate the effects of kot/kans by loading up on str/dex gear.

Also, just going off realism, axe kick and throw/owaza hyperextension should probably also be dealt with in a similar fashion, but I'm not sure how I would differentiate them from kot/kans.