All you need to do with the zucchini (hmm spelling? lol) is take it, chop off a small portion (no more than 1/2 an inch), take the peel off, & rubber band it to a rock or solid object so that it may stay in one place at the bottom of your tank. I did it for my loaches, but my ottos were the ones to go absolutely nuts!! No need to cook or anything. Then you can throw plastic wrap over the zucchini & throw it back in the fridge for later feedings.
Anne