I just got done reading a great post that talked about a spamable cleanse macro that could be applied to this:

/castrandom [target=party1] Water Walking,,,,
/castrandom [target=party2] Water Walking,,,
/castrandom [target=party3] Water Walking,,
/castrandom [target=party4] Water Walking,
/castrandom [target=party5] Water Walking

Should work. Might be able to make it a little more accurate by inserting toon names, or using castsequence, but party# would be a good generic solution.