First vinyl siding has tiny weep holes at the bottom of each course panel to allow moisture to escape.
How to seal siding from bugs.
Use caulk to patch small cracks in foundations and siding or use it to seal joints where the siding meets the roof or foundation.
There are a few spots in siding where you can successfully introduce insecticides.
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.
Add caulk around window frames as well as around any air intake or exhaust grilles.
I take advantage of these tiny holes using pyrethrin aerosols and an injection straw.
I d use dusts but the ready made hole is far to small.
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.
Caulk is cheap easy to apply and can go a long way towards keeping bugs out.