Random Seatbelt Alarm While Driving

My car was intermittently not detecting that the seatbelt is fastened, randomly while driving. Possible solutions:

cleaning the seatbelt tongue with isopropyl alcohol -- the quickest and I was surprised it actually worked, because the tongue did not look dirty

getting a seatbelt extender

replacing the seatbelt tongue -- seems like a lot of work

disabling the seatbelt check, on Alfa Romeo it can be done only through the OBD connector, but you need a special software (alfaobd.com, 50EUR, windows, android -- I haven't tried it)