Katalax can be applied to paws (and then shaken off followed by a flick of the tail and a dirty look...).
You can use liquid paraffin short term but it stop the absorption of essential vitamins so I wouldn't really recommend it for a cat who's not eating enough.
Lactulose is my "shifter" of choice but it does get syringed into the mouth. It's very messy if it gets spilt onto carpet
as it's a sugary solution.
I believe slippery elm is useful for regularity but mine can smell it on food a mile off.
Hope you manage to keep on top of it