Yes, homemade kefir is practically lactose-free dairy. Most of the milk lactose has been digested by bacteria in the fermentation process.
So when you drink kefir it has very little to none lactose content. And if you drinking homemade milk kefir, additionally you receive live bacteria that help your guts to process other lactose rich products.
Yep, that is something you can try at home 🙂