My Neighbors Secretly Used My Hot Tub For A Year So I Taught Them A Lesson

Their access would end permanently.

The second idea was mine.

I had trained as a chemist before moving into regulatory compliance, so I knew enough about compounds and skin contact to choose something harmless.

I found a food-grade dye that was safe for skin and would gradually fade within a day or two.

After prolonged exposure, however, it would leave a clearly visible green tint on the skin.

Harmless.