Those cartridges weren't made for refilling & the heating coil in them won't hold up long. That said, you CAN refill them once or twice & it'll work.
Put about 12 drops of
e-liquid into a small receptacle; if the cartridges come w/ little, rubber protective sleeves, they're perfect. Dip the end of the cartridge w/ the hole in it into the liquid then s-l-o-w-l-y lower the cartridge further into the liquid. The cotton inside will absorb the liquid & you can vape it. There are videos on YouTube about this that will show you.
As i said, it only works 1 or 2 times. While i'd recommend you move on to a different kind of vape, such as a simple pod kit, if you want to stay w/ a product similar to V4L's, they're still available.
You can find V4L cartridges at themagicmist.
Compatible batteries & cartridges are available from SmokeTip, ApolloECigs, & the Mig vapor section of VaporFi.
There are mint flavored e-liquids that might give you the flavor you want. You'll just have to hunt & experiment.
You can get flavorless nicotine from several online vendors. Probably not locally but maybe. They're generally for mixing one's own e-liquids, which takes you into a whole new realm.