When the seasons change I find my cats cough up more fur balls and I have to watch where I step so I don't end up with a slimy mess on my foot!
If your cats are like mine, they don't care for the oral fur ball treatment in a tube no matter what the label says about how tasty it is. My vet suggested offering a dab of butter on your finger for the more finicky cats and mine love it. Once or twice a week will make a difference.
Another trick is to feed them oily fish - mackerel or salmon, once a week and that will keep their digestive system running smoothly with less fur balls being coughed up.
Doing these two things will save you money and offer the cats more natural preservative free options for hairball treatment.