Are there any treat that help dealing with hairballs?

There is a malt based paste that you can give to your cat specifically for reducing hairballs. One I use is called 'Kittymalt' but there are many brands out there, ask at your pet shop. You can also buy anti-hairball dry food and anti-hairball cat treats.
Finally, brush your cat regularly to remove most of that loose fur.

If you mean treatment, withhold all regular pet food and feed nothing but strained meat human infant food until symptoms pass. You may make your own strained chicken by stewing skinless chicken parts in broth. We used chicken thighs. Reserving broth, debone cooked meat and puree in blender or food processor, adding a little of the broth if necessary to obtain a soft consistency, like oatmeal. Feed a couple spoonfuls at a time, more if tolerated. Also, have fresh water at hand. Keep paste refrigerated and use for 2 days only.

In order to lessen your cat's hairballs you should look for treats that contain petrolatum, mineral oil, vegetable oil or an equivalent intestinal lubricant.