When I have wood loaded in my CNC router, I don't use a lubricant. I just put the airflow dust shoe around the cutter, put the lid on the box to keep the noise inside, and start it up. But when I'm cutting metal, I need to use a lubricant to keep my end mill from getting too hot.
So I stand there with a spray bottle, in the middle of noise which I hate, wearing hearing protection which I don't particularly like, wearing goggles which I don't particularly like, spraying a lubricating solution as it goes and thinking there's got to be a better way.
Obviously, the correct answer is to automate the operation of the spray bottle. Pump, ultrasonic mister, spray head, pressurized vessel, whatever, there's a million ways. I need to figure out which of them most appropriately fits into the noise-and-dust enclosure along with my little CNC and its dust vacuum.
Meanwhile, is there a cutting lubricant in the form of a thick gloppy grease that I can smear onto the piece in the path of the cut, each part of which will still be there when the end mill gets to its location? I'm thinking of a form factor like Crisco. Hell, would Crisco work?
When I work metal it's usually cutouts in sheet metal (like toy gears from 1/8 inch brass or 1/16 inch mild steel) or single-pass pocketing (relief cuts 1/8 inch deep in 1/4 inch brass). For those operations, a particular location would only need lubrication one time.