Per CFR 46 169.529 lifeboats are required to carry one gallon of storm oil that can deployed from the sea anchor and an oil burning lantern capable of burning for 9 hours. It certainly is not in SOLAS. I have been sailing foreign flag and was not aware of this CFR.
Yea it calms the waves, they’re less likely to break and spray everywhere. From what I’ve heard from old timers it works, hopefully I’ll never find out.