Can you recommend a heating oil additive to break down water and keep the furnace happy?

I just bought an older home with an in-ground oil tank that’s getting up there in years. It uses heating oil type 2, and it’s been suggested to me that I find an additive to help maintain the system and prevent tank corrosion.

Do any of you have experience with these products? Can you recommend a specific product you’ve had success with? Are there some products you would avoid? Are there some things to keep in mind when using additives that I should be aware of? Thanks in advance for sharing your experience with me.