Yeah, I emphatically recommend Deoxit. I suspect a good cleaning of all relay, switch and fuse contact could have a dramatic effect for a lot of folks and it's what I would try before ordering a fix like this. I don't mean that as a shot against your product: it seems like everyone who has ordered it is happy, I just think there's a lot of value in exhausting the maintenance solutions first.
One of these days I should actually measure a before and after on some circuits with an older untouched rig and a multi-meter, just to see how much juice is being turned into heat in the fuse boxes.
