In this case, the technique I chose was to sneak up on myself. (Anticipating the inevitable comments, yes I do hide my own Easter eggs.)
So Saturday while eating lunch in the cockpit, in the sun, Jane raised the subject, "What's left to do to be ready for winter?" Reluctantly I confessed that the zinc still needed to be changed. The sun was shining, it was warm (58°!), and it was almost calm. I had to admit that this was probably the best opportunity I'd have before next June (and that would be way too late).
So while part me kept busy inventing excuses to put it off ("There's plenty of zinc left!" "It'll probably be warmer next weekend!" "We might not have any spare zincs on board!"), I just went ahead and got out the wetsuit and got ready to do the job. I was in the water before my lazy side could mount an effective defense. I confess that the beer I had with lunch might have helped, tho I'm not sure if it did so by slowing down my lazy side ("What the...? We're wet!"), or by impairing the judgment of my Calvinist side ("Oh, go ahead. It can't be that bad.")
But once in the water, the two halves of my personality briefly conversed and agreed that this was not bad at all... then I was single-minded again, doing the work. It took no more than 10 minutes.
And then I was back aboard in the warm shower.
So dear readers, how do you get yourself to do something unpleasant?
* Note: Jane filled up a tea kettle with warm water and dumped it down the back of the wetsuit* just before I jumped in. This helps tremendously - the suit doesn't fill up with cold water when you get in, since it's already full of nice cozy warm water. Try it!