@caseyliss I saw this for a project of mine and thought about your deck screw situation. This comes with magnet and hook attachments, and may have fit between the boards.
Amazon.com: Teslong Two-Way Articulating Borescope with Light, USB-C Endoscope Inspection Camera with 5FT Semi-Rigid Probe, Flexible Snake Scope for Home Repair, Automotive, Compatible with iPhone 15/16 & Android : Industrial & Scientific
Amazon.com: Teslong Two-Way Articulating Borescope with Light, USB-C Endoscope Inspection Camera with 5FT Semi-Rigid Probe, Flexible Snake Scope for Home Repair, Automotive, Compatible with iPhone 15/16 & Android : Industrial & Scientific