In December I ran across a Korean vertical that was recently moved from Puerto Rico from a place with no A/C. It had been stored at one point as well, and had obvious moisture stains on the keys. The tuning pins were so tight I could barely move them. The piano was not tunable. The DC rod in the bottom was unplugged.

I added a 25 watt DC rod in front of the tuning pins, and plugged in the bottom rod, and both ran 24-7 for two months.

I tuned the piano last week, after removing the rod in front of the tuning pins, and the combination of both rods drying out the piano for two months had loosened the pins enough tuning was possible. They were still tight, but tunable.

I left only the bottom rod running 24-7 till next years tuning.