Use the capacitive version of this sensor. Resistive sensors will destroy themselves due to electrolysis (their life can be extended by switching them on and off.

Capacitive sensor:

https://www.amazon.com/diymore-Capacitive-Corrosion-Resistant-Detection/dp/B07RYCNFZ5/ref=sr_1_3?crid=3TI3BIVNIOXXN&keywords=capacitive+sensor&qid=1647054248&s=lawn-garden&sprefix=capacitive+sensor%2Clawngarden%2C130&sr=1-3