That's actually how the OEM air filters were back in the '50s. You sprayed oil on the mesh and it filter the incoming air. From SAMBA - They simply have two grids, an exterior one and an interior one, whose grid allows the passage of dust and other small objects. The theory of how these work is that the woven wire mesh causes the air to change direction as it goes through the mesh and the dust is thrown against the "outside" surface of the bends and sticks to the oily surface of the mesh. Similar to how an oil bath filter throws the dust against the oil bath surface as the air changes direction through the filter.
The Original German Knecht air cleaners said "nach dem Reinigen einoelen" on them i.e. oil after cleaning.
According to Pelican Parts - Simply apply the cleaner onto the filter element, let it soak, and rinse. Once dry, the oil can be applied. Take care to not over-oil the filter. Refer to the instruction sheet for more information.