I believe they still need to design a jacket remover but indeed as Deery said they have a collar and hat remover.
To hide the different accessories click the cat's menu: Prims > Clothes > Select which clothes are visable (Each accessory saves 1 prim when hidden).
I can imagine you show the prims if you attach the cat to your avatar to cuddle or hold it and/ or visit friends while you hide it when your cat is roaming if the prims you have access to on your land are under pressure.
Should you have accessories hidden on a cat after which you send it to the online cattery and bring it back in world it shows all accessories it wears also the hidden ones.
In that case you need to hide it again if you want that
The free collar remover can be found
here »
It is the black collar box.
And the also free hat remover you can find
here »
On the ground right from the T-Shirts display this should remove glasses as well as they use the same spot as hats do in other words cats can't wear both.
I hope this helps!
P.s. Each accessory is 1 prim I wasn't sure from what you was writing if you thought it was more.