My current stock is in containers. I pour a bit of each into a glass jar and apply the mixture with a brush. I have not encountered any problems with the mixture staying there for a long time. It just separates a bit gravitationally, so I stir it before applying. With the chain, I now have gone to months between application. It possible that the mixture integrates better with the surface after few applications. I now went on to applying the mixture to anything that can rust, such as family car. It is amazing that it hangs on to wipers. I thought it would get washed off soon from such a place, but then the bicycle chain is also pretty rough.

Buying all components in containers can be pricey, but you may start by just spraying from a can into a jar. How spraying one layer at a time would work, I do not know.