Oil from the seeds of Camellia japonica is the traditional Japanese choice for protecting tools from rust: use it when cleaning, and as a regular protective coating. Leaves a lovely deep, non-oily finish, and it's odourless and tastless (handy for kitchen knives, but don't try drinking it.) 100ml- will last for years unless you drink the stuff ( but don't, it's mixed with paraffin).
We don't send this to customers in the USA. If this upsets you, take the issue up with the FDA. Sorry.
Niwaki Tip: The real trick with caring for your tools is to do it - it doesn't really matter exactly what, just get on with it.