HereForTheBeer: haha - it didn't work well. At all. I'll need to work on getting better weapons before I try that again.
The way I (finally) beat the Destroyer was:
* I found an ice sickle in the snowy underground region which really helped, as it shoots piercing missiles which hover in one spot
* Set up a little "destroyer house" away from my main house, about 30x20 squares to keep most of the little flying droids out
* Inside the house I put a campfire and a heart lantern to help with healing
* Made some strong healing potions as well and had some nice accessories to raise the invulnerability period after getting hit
* The main battle tactic was to stand in the centre of my house and then when the destroyer pounced, move slightly aside and then fire a bunch of ice sickles at it. That way I avoided as much damage as possible but it was still easy to cause lots of damage.
* From memory, the Golden Shower was also helpful to lower the Destroyers damage resistance
After beating it the rest were much easier, as I was then able to make a MegaShark which works great against most of the other bosses.