Have you considered using a spinosad solution? In the past, I’ve had luck with Captain Jack’s Dead Bug Brew.

I have’t played that before, but sounds something between NYT’s Strands and the Bookworm games; word search games. Maybe someone else knows something exactly similar.

https://www.nytimes.com/games/strands

https://www.solitaireparadise.com/games_list/bookworm.html

Edit: Celeste mentioned boggle. I found this one, but the board is smaller than your game above.

https://wordshake.com/boggle