There are a few spots in siding where you can successfully introduce insecticides.
How to seal siding from bugs.
Caulk is cheap easy to apply and can go a long way towards keeping bugs out.
Seal small cracks and gaps in your siding under 1 4 inch wide using an acrylic latex caulk.
I d use dusts but the ready made hole is far to small.
I take advantage of these tiny holes using pyrethrin aerosols and an injection straw.
First vinyl siding has tiny weep holes at the bottom of each course panel to allow moisture to escape.
Paint works well over it.
Instead i d probably just let the siding thoroughly dry in the sun checking for signs of bugs during that time then go ahead and use it.
And unless you want to cover the wood with epoxy to completely seal everything in i don t think there s an impervious finish against insects.