Anyone Propagate Java Ferns?

I accidentally knocked an adult leaf off of a java fern in February. I put it in a small cup half full of water with a lid on and kept it on a shelf. After a month I opened it up and found 3 smaller java ferns growing from the midvein of the leaf. I removed them, then put the leaf into my breeder net that I have guppy fry in. It's currently growing a few more, and the leaf isn't decaying.

Does anyone else propagate java ferns like this? Is there a better way? Any techniques or ways to grow them out faster?

Thanks.