I have a thrips problem.. its been an ongoing battle from day one.. seems to be impossible to get rid of. I tried lady bugs, but if you have ANY holes in ur room they will disappear within a few days...make sure you've tuct taped well. No cracks around the doog. Mine all escaped from non-sealed room... excaped through wire holes.
As for lady bug poo... I wouldn't worry about it because thrips leave behind TONS OF POO!!! Id much rather have small amounts of lady bug poo than tons thrips poo! lol But lady bugs munch on the thrips alot. There is also a Thrips Predator that you can buy, they sell them in bug factorys along with lady bugs. They are a little more expensive though. Lady bugs eat different kinds of bugs, so its good to use if you are having a multi bug problem.
I use Einstein oil, its the most effective oil. Most neem oils are NOT as potent...make sure you look at the oil you're buying before you buy it. It should be very thick, if it isn't they are probably selling you something cheap and non effective.
Seems kind of odd that you are noticing the thrips when they're in bud, usually its a problem from the beginning when they're small. Make sure the room is bleached from floor to ceiling when everything is out.
As long as all ur leaves are not falling off and curling from the bugs it should be okay and you can spray while they're in bud, it would not hurt the plant.
Hope this helps.