@mervy just like any other water immersed device, you will at least have to disassemble it, clean everything with +90% isopropyl alcohol. After that, replace the battery and re-evaluate. Water damaged devices are the toughest to fix since you just never know what got shortened out. Added problems here are that the Airpods are difficult to disassemble. Take a look [https://www.youtube.com/watch?v=3vY3wuE7WVU|on here] starting around the 2min mark or [https://www.youtube.com/watch?v=2jV-9aHVdNE|on here] around the $30 min mark.