Kerosene Wash for Oil Cup Air Cleaner Question

Inherited a 1959 D14, it was used pretty sparingly for the past few decades, 30 hours/year at most I would guess, and light work at that (riding around yard with grandkids, occasional pulling of cultivator).  With that being the case routine maintenance can fall off, so I'm doing a full course of it now.

Bought the owner's manual, which states to clean the air breather element once a year with kerosene.  My plan is to clean out the cup, put the cup back on, take it off the tractor, fill it from the intake until it begins to come out the port to the carburetor, then let it soak over night.  Next day, agitate every now and then and drain.

What I don't know is this.  After I drain the kerosene, what (if anything other than fill the cup with new oil) do I need to do before I put it back on the tractor and fire it up?  Do I need to rinse it, or let it sit draining for a certain amount of time?  Read some unpleasant stories of people using gasoline to clean it, I'm not doing that, but want to be safe with kerosene.  Any suggestions based on what you've done would be great.  Somewhat nervous about doing something that could cause a problem, i.e. blow me up.

Now that I think of it, maybe after draining the kerosene I'll fill the cup with oil and swish that around a bit, then discard that to rinse out the kerosene.