[Inconspicuous Kitty]

While a lot of 10* weapons are good, there's a number that just don't reach the bar in terms of matching up with, well... anything. In some cases, there's even clear reason not to grab one over a lower star item, despite them supposed to be the 'top tier' items. I have no problem with lower stars being better than tenstars, especially for a given build - but when they're so undershot that there is a clear reason not to take them over something else, that's what raises some alarms for me. Perhaps the nature of other tenstars can be brought up in another thread, but this is for the one and only Acidic Claws

The Acidic Claws. It gives a measly 12 Acid damage on hitting enemy with a basic attack at full UL. Not only that, but it cuts you off from the Bloody Palms (which effectively does it's job but better, lasting for the remainder of a turn) or any other subhand that deals damage (Insulated Burning Bracers are a good example, even if they're fists only - 10 damage with no downsides beyond a slot), only qualifies for melee weapons, AND kills your durability upon use. If this had an additional effect, such as burning enemy durability (armor removal is a tad common but it'd be a good effect too), or perhaps shutting down any alternate, non-defense reductions for maybye UL/4 rounds, this would be a more fun and usable items. Alternatively, the damage it deals could be raised from UL acid damage to something like 3x UL acid damage.

[Lolzytripd]

maybe 3x UL % unresistable acid attack on hit.

or maybe it could use an active skill

Coat in acid, changes weapons damage type to acid, adds half of acid attack to weapon power.

[Autumn]

I think it should either chip away at enemy durability or be 2+UL*4% Acid ATK on hit.

Alternatively as you said, it chipping away at Phys.DR would be a good option too.

[Neus]

I could see them getting a buff in some way. The UL was a little more relevant pre-GR.