Sometimes the most creative ideas are the wrong ideas. Open top-up containers like this are magnets for contaminants and can wreak havoc when used on small sumps.
This is an oil top-up container made from an old coffee can, hose clamps and copper tubing. Creative, but probably disastrous to lubricated machinery.
Consider using a convenient “one-shot” or top-up container. Some oil suppliers can deliver labeled containers filled with prefiltered oil that meets a specified cleanliness level. These disposable containers are convenient, reduce contamination, minimize product mixing and increase the likelihood of proper application (correct oil in the machine).
An alternative storage solution is to buy clean plastic jugs to fill and label yourself. Some containers have a built-in spigot and don’t require a funnel for use. Funnels, like open top-up containers, are magnets for contaminants.