Mine

proc unregchan {chan} {
  global srv sql
  mysqluse $sql(hand) $sql(db)
#  if {![catch {mysqlexec $sql(hand) "DELETE FROM oper_module_regchan WHERE chan_name = '$chan';"} err]} {
   if {![catch {mysqlexec $sql(hand) "SELECT chan_owner FROM oper_module_regchan WHERE chan_name = '$chan';"} err]} {
    putlink "MODE $chan -ntispm"
    putserv "PART $chan"
    return 1
  }
  return 0
}


handler:

proc unregchan_handle_msg {nick host hand arg} {
  global botnick
  if {[llength $arg] != 1} {
    putserv "NOTICE $nick :Invalid arguments. /msg $botnick help unregchan"
  } else {
    if {[unregchan [lindex $arg 0]]} {
      putserv "NOTICE $nick :Unregistered channel."
    } else {
      putserv "NOTICE $nick :Failed to unregister channel, please contact an operator."
    }
  }
}