I'm over 5 years on my Anco refills (and got 4 years on the OEM), but they're starting to split at the top end, so I'll put on new ones when it starts raining again. It helps that they're mostly shaded by the trailing end of the hood. I don't put anything on them, but I wash them when I wash the car, and I use Rain-X on the windshield, so I can usually leave the wipers off (at speed) or on intermittent.
I don't see how alcohol can do anything but dry out the rubber, but if you needed to wipe the wipers off with something then use soapy water...