While larva survival is highly unlikely, tiny, post metamorphous juveniles can survive.
I had an around 10mm baby marine betta survive in a tank with an adult marine beta pair and a fully grown clarkii pair hosted by a 25 cm green BTA. By the time he got lost he still had the white sides.
The little guy went through the overflow and through an about 5 m long aptasia infested piping system with it's outflow straight above the clarkii's anemone. When I noticed he was missing (I only had a handful in that first batch and counted them daily) and realized where he must have gone, I chalked him off as a loss, either caught by one of the humongous aptasia or swallowed by the clarkii (for them he was just snack size as they would gulp down frozen gobies with a 1/4" diameter and feeder shrimp with ease).
A few years later, after cleaning the back glass of the tank (it was actually the 500 liter sump of a 750 liter room divider tank) I was surprised to have a halve grown marine betta looking at me. At first I wondered how a big marine beta could shrink that much so quickly, but when the other two also showed up it was clear that I had one extra fish in there. At first I thought one of the many larva that went uncollected must have somehow survived but then I remembered the little lost fish and it was clear that he must have survived. He must have fed off the pods in that tank until he got large enough to collect the frozen food the other fish had missed. Surprising was also that the adult pair didn't harass him (her actually). That's when I knew that can actually keep them in groups.
Clownfish babies should be as well be able to survive when there is a suitable anemone in the tank. I will definitely try that out when I have babies of my percula.