As titled:

Activities I tried:
- Unit is always ventilated
- No books or papers around
- Washroom is constantly dry
- Even tried to spray insecticide on it everytime, they just don't go away.

Note;
Cant remove wood furniture, as some of it comes together with the unit.

Do I start using the AC to dehumidify? Not an AC user.

What are my options?

silverfish isit, used ubat gegat, those stinking white balls

Nope - Silverfish is the long looking with the tail ones right?

These are small - almost thermite looking.

I have the same issue. Usually this is cause by ventilation problem which causes moist in air . So your wall and plaster ceilings as moisture . You need ventilate your area, if not it will come back. Once u ventilate the place , u can get pest control to spray poison to make sure the eggs are gone.

Solve ventilation issue before u call pest control.

You live in condo or landed? If landed, I suggest you install turbine to ventilate the hot air ya. Ventilation means u need 24 hours buka window. Impossible for me la so I got the issue.

If you live in condo, I suggest u get Ac or dehumidifier