If you didn't feed them maybe, just maybe they would. I know some goldfish will eat it. I used to throw handfuls in silver dollar tanks when I had my shop and they macked down, but neither of those suggestions are helpful in a planted tank. I have a couple of tanks 100% duckweed free right now best I can tell, and I'm paranoid about nets, my arm, anything going in there that's been in the others. But it's easier to rid than Java moss at least since it floats.
Nothing good happens fast in an ecosystem.