Reading between the lines on re-applying after a rain:
The label indicates I can only apply 6 times during the growing season. Does reapplying after a heavy rain count against this total, or do I get a "freebie"?

Just applied less than a week ago, and new CLM activity has appeared after a heavy rain. I'm struggling with timing since we are in our summer rainy season, and it is hard to have a 2 or 3 week interval with no rain -good problem to have, I guess.

I'm alternating spinosad and neem on 14 day schedule with a hose end sprayer (couldn't figure out a good way to get the desired 50/50 concentration of each as I do with my tank sprayer).

C'mon, gang. Who doesn't like a good CLM thread? anyone?

I don't use Spinosad, so have no idea.

I use Spinosad and a light Horticultural oil mixed together and sprayed at the same time. I thought the Spinosad was systemic. If so, it shouldn't wash off if it has had time to penetrate the leaf. I don't know how long it takes.
I started spraying every two weeks since the second growth flush. I've had almost not CLM damage this year. This summer has been very rainy here too.

Bayer Advance

I put it in the ground in early June, again in early August if need be.

It is systemic in dogs, when fed to them for flea control. *wink*

In plants, however, it seems as though it is not highly systemic when used as a foliar spray, although it transported through the layers of the leaves to some degree, and thus MAY not need reapplication after every rain. That might be less true for waxy leaves such as citrus, though. It can also be used for systemic control of some critters, such as mites, in hydroponic systems, but its root absorption seems to be very low in soil substrates.

I don't personally use the stuff (except for with the dog), due to its high toxicity to bees, but that is out of an abundance of caution, since the threat is greatly reduced if not eliminated by proper application during times of non-forage - or, presumably, to citrus not in bloom. Its harm to beneficial predators and parasitoids is relatively low, and it would be one of the first things I would go to if I had an actionable problem and neem wasn't working. CLM just doesn't present much worry for me; a bit of sesame oil seemed to deter the moths from laying eggs on the young plant they most favored this summer, and the mature trees don't seem greatly bothered by it. This is, though, the experience of a citrus novice.

I applied it just after dusk and the citrus are in filtered sunlight for much of the day, so burn hasn't been an issue, although I tested a few leaves before going "whole-hog".

You're right about the expense though - I used it because I didn't happen to have horticultural (or vegetable or soybean) oil on hand, and since it was just one young plant and just three times over the summer I didn't use much, but it probably wouldn't be practical to scale up.