Safe Deposit Boxes & Dehumidifiers

I currently store all my photographic material in my bedroom cupboard. The temperature is around 20 C and the RH is 60%. I have been researching ways to bring this figure down to 50%.

I would like to know if anyone has tried storing their photos and slides in a safe deposit box at home (not rented from a bank) with a dehumidifier inside?

What has your experience been like and is it a storage method you would recommend?

Would you recommend zip-lock bags for added protection?

Appreciate any feedback.