What is the smell of an oily rag?

In New Zealand, "the smell of an oily rag" refers to an absence of resources (i.e. There is no oil left, just some traces of it). Most often the term is used in the larger expression "running [or living] off the smell of an oily rag." If something runs this way, it is done with little financial resources. Volunteer and arts organizations often run this way.