Malfunction Indicator Lamp (MIL) overactive

Can’t get the MIL to permanently turn off. Tried wiping the gas cap clean, tightening until my fingers are numb, etc. This usually works for a week or so then comes back. Can I safely ignore this nuisance?

You do realize that this light can indicate any one (or several) of hundreds of different problems, most of them not related to the gas cap.
You need to get the OBDII code(s) read and report it back here. Some auto stores will do it for free. Be sure to get the code, and not the description of what they think it means. The codes will be a letter followed by four digits.

With tongue firmly implanted in cheek, I could suggest having the bulb removed and pitching it in the dumpster.

Tongue out of cheek, why are you convinced the gas cap is the problem? It may be on for any one of hundreds of reasons.
Get the car scanned (AutoZone, Checkers, O’Reillys, etc.) will do this for you free and find out what codes are present.
(And I’m assuming, correctly or incorrectly, that this has not been done.