Erm, that's Mass Op not Mass Deop.
I am not too sure on what you meant, but try.
Code:
alias mass {
  if ($1 == DO) { set %mass 0 | :jump1 | inc %mass 1 | if (%mass > $nick(#,0)) { goto end } | if ($nick(#,%mass) == $me) { becho Mass De-Oping All Ops!! | goto jump1 } | if $nick(#,%mass) isop $chan mode $chan -o $nick(#,%mass) | goto jump1 | :end | unset %mass }
}


on *:JOIN:#: {
if ($me isop $chan) { mass DO }
}