Firewall command for removing all sources and services?

I have a firewalld zone set up like so:

# firewall-cmd --info-zone internal
internal (active)
  [...]
  sources: 1.1.1.1/24 1.2.1.1/24
  services: ssh custom_service
  [...]

Is there a command that will remove all sources and all services from this zone without specifying them?

I'm trying to write a script that cleans out the zone entirely, then writes out the sources / services correctly for a new zone.

I am looking for something like:

# firewall-cmd --zone internal --remove-source=*
# firewall-cmd --zone internal --remove-service=*

Is there any wildcard I can use in this way?