When sealing utility access points to prevent American cockroach entry, what material should be packed tightly into the void before capping it?

Answer

Steel wool

The recommended practice for sealing pipe penetrations is to first pack the void tightly with steel wool before capping the opening with expanding foam or caulk.

When sealing utility access points to prevent American cockroach entry, what material should be packed tightly into the void before capping it?
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