Actually the FCC has the weapon!
It's really simple. Rather than bend over backwards trying to give carriers 90% of what they want by avoiding fully using the Communications Act for what it was meant for, just use it fully. Define Verizon and AT&T and Comcast etc as common carriers complete with full regulation and line-sharing requirements for copper, coax, fiber, and wireless!
Its not regulation, its simply the law. The challenges that the FCC keeps losing are because the FCC tries to find a middle way between regulating them as common carriers which the law was written to do and not regulating them at all which is what the monopolists want. The FCC should completely implement the Comm Act and then lets see if the Corporatist DC Circuit Court can try to figure out a way to rule in Verizon/Comcast's favor again given that the FCC took the law exactly as intended and implemented it like they used to do.
Afterall if a baby bell is not a common carrier, then nothing is a common carrier.