Not really, this is more akin to using a laser to destroy something at a distance. The neutrinos would interact with soil near the weapon, some of these reactions would produce neutrons which would go on to induce fission in the weapon, destroying it.

The idea that solar neutrinos impact decay rates generally assumes that neutrinos are directly interacting with radioactive isotopes (usually through some unknown physics).

It makes no sense to me that half-lives can't be affected by anything. Do you have a source for a discussion of this?