Alright, here is my anti-rust guide. It is seperated into two sections, weapons and items. However, i do not explain where to get oils... that will come another day.

Weapons
Protecting weapons is rather simple, all you need is oils (either fish oil or snake oil). One oil will protect a piece of weapon for one quested day (if you play and oil today, and don't play till 3 days from now, it will be as if one day passed in DC) and a single piece of weapon can hold a max of 5 oils (thus it will be protected for at least 5 days).

Items
There are two forms of "protection" for your items. Both can be found in the queen's court. The "Minor Blessing" costs $100k marks and only protects the items that you have equipped. "Major Blessing" requires you to have already activated the minor blessing and it costs an additional $500k. The major blessing adds protection from rust to the items in your pack.

If you get just minor blessing, the next questing day, you lose the minor blessing. If you have both blessings, you will only lose the major blessing and so you will only have to pay $500k instead of $600k for both blessings.

Note about blessing on oils on weapons
Oils on weapons will "wear off" one per day UNLESS you have blessing(s) active. Then the oils will remain on the items until the day in which you forget blessing, or choose to go without.


So what is the best combonation of protection?
Before you "sleep" for the night, make sure you have both blessings and then, take everything you wan to protect from rust (in terms of items) out of storage and put it in your pack. Weapons can remain in either location as long as you remember to put oils on them but the oil will not be used up if you keep that weapon in the pack.