SSH config partial allowing to hop through an arbitrary host

throughssh

# Generic throughssh command
Host *.throughssh.*
  User root
  ProxyCommand ssh -A -q `echo %h | sed -e 's/^[^\.]*\.throughssh\.//'` -W `echo %h | sed -e 's/\.throughssh\.[^\.]*$//'`:%p
  GSSAPIAuthentication yes
  ForwardX11Trusted yes
  StrictHostKeyChecking no
  UserKnownHostsFile /dev/null
  LogLevel ERROR
  SendEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES
  SendEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT
  SendEnv LC_IDENTIFICATION LC_ALL LANGUAGE
  SendEnv XMODIFIERS

# Much easier alternative: some-reachable-host[/inbetween-host]*/final-destination-host
Host */*
  User root
  ProxyCommand ssh -A -q $(echo %h | sed -e 's/^\([^\/]*\)\/.*$/\1/') -W $(echo %h | sed -e 's/^[^\/]*\///'):%p
  GSSAPIAuthentication yes
  ForwardX11Trusted yes
  StrictHostKeyChecking no
  UserKnownHostsFile /dev/null
  LogLevel ERROR
  SendEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES
  SendEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT
  SendEnv LC_IDENTIFICATION LC_ALL LANGUAGE
  SendEnv XMODIFIERS