Tadpole would know what you were planning and just stay inside the nellon
True resurrection will resurrect someone who got his brain exploded with all ailments and alien parasites removed.

Technically, it should also cure Gale's chest problem.
Funny

Gale's chest problem and the alteration of those tadpoles have actually kind of the same origin. As it's the same all-powerfull cosmological-rule-changing magic.
Netherese Shadow magic isn't a cosmological-rule changing magic, it's normal magic that use energy from the Shadowfell.
Without the Shadow Weave (which haven't been fixed yet,
and I'm pretty sure that's what Gale is plugged into which is why he has to feed it, as feeding it magic was how Shar was trying to fix it
), you have to use the normal Weave to cast it like any other magic too.