Work at a hotel. We have them occasionally. When a room is found to have them the room is put off market for 24 hrs as are any adjacent rooms either beside or above/below. They’re chemically treated at the beginning of the 24 hrs. This includes destroying ALL linens and chemically treating any fabric surfaces as well. The rooms are “flipped” with every headboard and painting removed from the walls during treatment. The mattresses have bedbug prevention (bedbug covers) already on them but they’re inspected and replaced regularly. At 16 hours the rooms are checked and verified there are no active bedbugs. The rooms are then steam treated for good measure. At 22 hours they’re cleaned with special vacuums to prevent relocation.
If a guest is in the room when they are found then all of their clothing and laundry are heat treated and inspected.
This seems to be the industry standard for large corporate hotels. I work for one of the largest in the world. This is our SOP. It’s expensive but we don’t end up with infestations so it apparently works.