The Organicide sounds like a good product. I've never used it, but I do use Fish Emulsion which can leave foliage sticky..it doesn't last too long..
Do you mist/shower plants? If so, by doing this Organicide should eventually wash off, BUT, don't hose off until all sign of scale's gone. There may be info on the container advising when you can hose off plants. But please follow container directions.
BTW. scale leave a sticky residue, so are you sure it's not the scale that caused this problem or did it happen after you applied the Organicide?

I give my citrus a last feeding in Oct (when they come indoors) using Osmocote. It's supposed to last 3 months. I also use Fish Emulsion as an insect repellent and foliar feed. You can also use a 3 month Citrus ferilizer..Toni

Hello, on your lemon tree- get a spray bottle & dilute alcohol & water an spray your tree it will kill the scale's & won't harm the tree - or you can use diluted Windex -I had them bad one year & I was told to get rid of my tree & I said nope my tree staying wit me & that's when I was told about the Windex- My old tree lives on my bay window & I give it food when I think about it-I got 7 yellow lemons on it an 2 walnut size green ones an when I see the scale's I just spray with the windex/ water & my tree's over 50 years old. Have a Nice Day, Slim

Slim,
Thanks for the tip. I have my citrus inside now. The scale was never very bad... I think I had only around 20 on the tree, but I have been watching them. I squished them on the edge of the citrus pot... hopefully thier friends get the idea ^_^. Thanks for the windex tip. I think the organicide may be a bit heavy for the citrus leaves. This is almost a month out, and the leaves are still a bit sticky (and the trees were in the rain, are misted and such). They dropped a few leaves too, but that might be due to me moving them in a little late (didn't know cold nights caused leaf drop). It's great to get so much help, consitering that it's my first year with citrus. Thanks again.
AriesF5