Hillbilly, he's talking about dust infiltrating the open architecture of an alternator. Not a place you want to spray anything wet or anything dust will then stick to.
And I'm not talking about jamming a spray nozzle against a bearing seal. Just a couple blasts aimed in the vents of the alternator. Don't know about Ford gear, but the modern GM alternators are really quite open.
If I ever get around to my grill guard / 3" tube bumper, I intend to go old skool and turn it into an air tank. inset ends with schrader valves and air couplings. A small coiled air line and nozzle would make easy work of blowing out air filters etc. Would make a nice solution with a mounted compressor too, hard plumbed.
here's a similar idea for a bumper tank, the idea has been around since at least the middle 80s in off-road magazines.
I've got a ~5gal thin-wall tank that I used for hobby airbrushing for many years, been trying to offload it for many years. Would make a good tank but there's no space in my Suburban I want to surrender to it.