There's no such thing as a daft question! For bug and parasite control, I use permethrin. It comes in concentrated form, then you mix with water and apply with a spray bottle or pump-up sprayer.
I remove all birds from the loft, remove all bedding from floor and nest boxes, then spray all surfaces (especially corners and cracks where bugs hide) until the surface is just damp. Let it dry (depends on your weather but anywhere from an hour to a day). Then put in fresh bedding and the birds go in last.
I use permethrin on the birds also. Just a small squirt of the diluted mixture under each wing and one on the vent area and your good for months. If you have very young squeakers in nests, you'll have to hold off.
That's my program and it's always worked with no I'll effects. Wear a mask while spraying though. And avoid getting it in your birds' eyes when spraying them. It helps to have an extra pair of hands.
