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Good question. Klutz ignores the effects of the item you're holding, meaning you can change moves whilst holding a choice item. The issue can be viewed in two ways:
Allow Klutz since it can be used as a creative way to take advantage of the rules; or,
Disallow Klutz since it goes against the spirit of this tournament;
I'm going with option #1 here and allowing Klutz. Though, only mediocre Pokemon like Lopunny have Klutz, so if you really want to use Klutz, be my guest! I'ved edited the OP so everyone is aware of this change.