No, in my opinion, I think it's a very bad idea and in the long run because...
- Olive oil is going to rapidly increase fouling, and can shorten the service interval to a point where the firearm may need much more frequent cleaning
- Poor thermal resistance - poor performance in hot-hot, and so/so performance in cold-cold
- Oil migration --> when the oil leaves the area it is needed at, this can mean damage to components not intended to be oiled, a very gunky mess, and accelerated component wear
- Reliability concerns stemming from poor lubricant performance and/or accelerated fouling
- Toxic fumes if the oil is heated past its smoke point, which firearms can easily exceed
- Food grade oils go rancid over time
Olive oil and many other food grade oils tend to provide poor rust protection at best, and rapidly will accelerate fouling. Compared to a state-of-the-art dry lubricant/protectent, the difference in functional performance and upkeep is going to be very dramatic. I would not be surprised if a firearm treated with one of these advanced products would provide a service interval 15-30 times longer than the service interval of the same firearm treated with olive oil. That is a lot of time saved on cleaning!
Most food grade oils do NOT have the thermal stability needed for firearms, and upon reaching a certain temp these oils will be useless. In some cases, exceeding the smoke temperature can cause burning food-grade oils to release slightly toxic fumes. Olive oil has a very low smokepoint versus most other food oils. On the other end, these oils will have inconsistent performance with extreme cold.
A huge concern is oil migration. These food grade oils are not formulated to resist oil migration, and so they can easily move away from the contact areas you wish to protect. That oil can move to areas that you do not want to have contact with oil (ex: fine cosmetic finishes, the shelf in your safe, or the inside of your gun case. As the oil progressively migrates, there is an increasing chance of accelerated component wear (however, just how big of a risk this is isn't easy to quantify.)
If someone is worried about toxicity, there are several advanced products on the market that have a very, very low toxicity. The current product I am using is Corrosion-X. Eezox is also excellent, and it becomes less toxic once it has dried, but it still is not non-toxic. Hornady One-Shot dry lube has floored me with performance that IMO is even better than many of the current premium products on the market, but I am not sure of its toxicity as I have not seen LD50 values via the MSDS for that specific product. What is especially noteworthy is that, while it is still a dry lubricant, it provides outstanding lubrication that many other dry lubricants struggle with.
IMHO, these newer products may carry a slightly higher price tag, but they are justifiable due to dramatically better rust protection, thermal stability, likely better reliability/consistency, tendency to reduce (even eliminate) migration. Additionally, the very long cleaning intervals they allow is a huge convenience. While the CLP I've used is certainly great, One Shot not only improves in all areas across the board, but these improvements are very pronounced. YMMV