Well... I'm not kettlegeek, so this is not a definitive answer by any means, but I hate kettlebells with smooth handles. I find them hard to hold on to, and often times do the increased movement, they cause increased wear on my fingers and palms. I purposely rough up the handles on my kettlebells. Some course grit sandpaper does a nice job of creating a surface that is smooth enough to let then handle slide through your hand, but still course enough to hold some chalk and offer some grip.
That's just my 2 cents. I'm not sure if it's the solution to your problem, but personally, I like sanding kettlebells.