You could buy items worth lower than 25K and just drop them in the wildy, have your friend pick them up as you drop them. Takes a long time, yes, but thats really the only way I know of :S
With the table method being patched, I think the party room is the only option. It takes a while to pop the balloons but there is no world-wide announcement. Might be faster than buying <25k value items and dropping them. You can put noted items or GP into the chest.
Just checked and it works.
EDIT: The balloons do eventually disappear, so I suggest multi-logging two non-trade limited accounts to pop the balloons faster.