I was thinking about covering the cord with something, but it seems like it'll be less noticeable to just glue it to the gap in the tile pattern.

These aren't real tiles but peel and stick, so no worries about damage.

I'm only worried that the sealant won't hold, or could corrode the cable, or the tiles

I got this https://www.amazon.com/Silicone-Grade-Strength-Sealant-Clear/dp/B00NU6VN6G sealant to fix a crack in my freezer, and since I have a whole bottle of it and it dries fairly clear, I thought I could just use a small amount of it for this.

Is that a terrible/stupid/diwhy idea?