Maybe. Typically floating plants have high co2 demands so you would need to make sure there was plenty of co2 & enough light for it to grow. Anchoring it in the substrate would be an issue to. I doubt it would spread out very well either.
Since many floating plants have really short water roots I'm not sure they could take up the nutrients they need . they would also be hard to keep in the substrate.
Nutters suggestion for a substitute is excellent.