Pathfinder: Rise of the Rust Monster
A slightly amber coloured resin-like liquid in small, round jars
This resin protects a weapon from harmful effects that corrode or melt weapons, rendering the weapon immune for 24 hours. One pot can coat one two-handed weapon, two one-handed or light weapons, or 50 ammunition items. Applying it takes one full round. Immersing the weapon in water or similar liquid washes it off.