If your spray had any oils and I tried a few sprays with pyrethrins. All I could find had some kind if not neem oils. Good for spidermites but bad application. When you soak the plant with spray it will kill it . A light spray will get buy but only slow down the bugs. Get some foggers, like dr. doom. Just do a search they have small ones for small rooms. They did not seem to hurt the plants about 12 inches tall at all. I just went through this with a friend. The foggers need two hours of dark and please unplug all electric. I watch Mytthbusters. The light being on did not help.
You need to break the life cycle of the thrip if that is your bug. I know with spidermites eggs hatch every 4 days. Adults have to be 14 days old to lay eggs. So 4 foggers at 4 days apart. All signs gone at my friends.
Hope this helps.