IN the Golden, Olden days of CB, the jargon you say "barefoot" or "Stock" is more related to how someone were to operate their equipment...
It's lingo, slang - jargon...
IF you ran a Linear or Amp you would call it a "Foot warmer" or a "Boot" - like you'd use for outside - something that lasts for the journey. Think of it as a signal traveling out - it takes a journey - if you use a "boot" the signal can travel far - farther than without using one.
IF you traveled a lot, you could get blisters from walking - so the moniker of "footwarmer" also segued into what we call amplifier - and it also rivaled it's truer nature of an accessory that did get very hot as you used it - it also meant the driver was also a risk taker or speeder because of the notion that if you have one - you use it to step over the noise and chatter - like you'd put your foot into the accelerator pedal to go faster - make your vehicle work harder - you worked your feet to travel. "pedalpumper" was another...
You also had the problem of travelers that would be going opposite ways along the highway - a quick bear check or speed radar traps (Kojack with a Kodak was one of an officer using a radar gun to catch speeders and mail them the ticket if photo radar too) could help those close by. But to get the word out of a possible backup due to an accident or delay - a "boot" came in handy then, for the driver to get the word out about problems they saw behind them, but others travelling in the other direction would not - and so it helped in traffic and busy highways during rush hour to have such a device to help spread the word and help drivers avoid delays.
So "Boot" referred to amplifiers for a CB'er to use to "talk" for longer - greater, distances than without them.
Like traveling along a highway - what we'd call a Semi following too close, would be called a tailgater today, but back then - it was a form of "drafting" to keep fuel costs down and allow a vehicle to nearly "Draft" behind another and they called that "Keeping your Tail feathers warm" - cars did this too, so it clung to the drivers , of the female persuasion, that also followed closely to semis to obtain fuel economy. IT also served as a warning or guidance for the "convoy" of vehicles - as it a driver would have to be extra careful of their tails - because of the close quarters the trailing drivers were in distance from what they drafted off of.
So, as drivers get closer together as they travel in the same direction - their "boots" got turned off as they got too close and their radios "overloaded" from the stronger signals close-by. So they'd oftentimes ask the other driver if they were - or could they be - barefoot so they can talk to each other without sounding all garbled up or overloaded in each other receive.
They also could ask if you had, "uppers" "lowers" or "funnies" so they could go to another channel on a closer frequency but not in the CB band (40 up or 40 down meant that the guy had a radio with "capabilities" so they could go out of band to converse as needed).
So in a way - "stock" referred to a no-frills radio that you just bought back at the local Truck Stop or Radio Shop and it has not been modified yet.
My 2 cents - woof, there's a lot here ... Keep the change to help pay the toll's on the turnpike further down the road - past the billboard sign that's got a County Mounty parked behind it in a Plain Wrapper taking pictures of your backside as you go by that mile marker - be sure to smile and wave - tell them Handy Andy says hello...
