I've been using Katalax on my semi-longhaired cat for the past year with okayish results. However, the mixture can vary a lot between tubes, often being much too thick to squeeze out, and far too easy for my cat to flick off his paw. So I decided to try out Defurr-UM. It's a lot cheaper than Katalax and comes in a bigger tube.
The mixture is just the right consistency and doesn't flick off like Katalax. It rubs on nice and smoothly, and my cat licks it off instantly, unlike Katalax, which he would try his hardest to flick off before finally giving up and licking off what was left very reluctantly (while giving me a dirty look...)
As he's been retching a lot recently, I used the dose of 1/2 teaspoon a day for 3 days (to bring up the existing furball) and will give him a weekly dose of 1/2 a teaspoon to prevent further furballs. If you're looking for a cheaper alternative to Katalax, then I highly recommend Defurr-UM if you need to 'de-furball' your cat on a regular basis.