Honestly I havent heard about DeOxit before, somebody suggested it on this forum earlier. It's amazing! $17 bottle solved the following issues so far:
- auxiliary pump working again (nice warm cabin soon after starting the car)
- both seat belt tensioners functioning again (no airbag checklight)
- seat occupancy sensor working again on passenger seat (no airbag checklight)

Seems like a lot of problems caused by oxidation on connectors, now I just spray it routinely into any connector I unplugged.

Highly recommended to try it before replacing a part.