Does larva lace float on a dry fly (w/ floatant?) or does it make the fly sink due to its weight...

If thats not the case, does is help keep the fly a float because it doesn't absorb water?

I also wonder about the hollow laces, If they have air in them when you tie them on the fly, doesn't that mean they would float the fly like corks on the water?

Also do you know of any dries tied with them??

Thanks for responses.