Synthetic motor oils do contain detergents which will process carbon fouling. They don't do much of anything for leading or copper fouling, however. So his synthetic motor oil isn't so far off from a simple, HIGHLY DILUTED carbon gun cleaning clp type product like Hoppe's gun oil or Rem oil (these tend to have extra solvents too, which the synthetic motor oil does not).

In other words, it works, kinda, but not as well as other products. And it won't do squat for lead or copper.

For lubricating, synthetic motor oils are thicker than gun oils, so they stay where you want them longer, but they don't have the lubricity of finer gun oils, so they heat up and foul faster, and don't protect your parts as well. I ran Mobil 1 synthetic motorcycle oil (gotta look at weight - have gallons on gallons of it for my sport bikes) in my AR's. Works fine as a lube until it gets cold, and cleans the action well, where there isn't any copper or lead to deal with.

You can polish your jewelry with toothpaste (fluoride & abrasive aggregate), you can lube and clean your AR with Mobil 1, you can clean your battery terminals with Coke-Cola, and you can drive a nail with a socket wrench... Working "ok" for the task doesn't make it the right tool for the job.

After all of the cleaning I've done, and all of reading on the chemistry and testing for myself (helps having a degree in chemistry too), I'm happy as a pig in schitt to use exclusively Hornady One Shot dry lube & Cleaner, Butch's Bore Shine solvent, silicon patches from Hoppe's, Frog Lube, white lithium on triggers, nylon brushes and brass jags from Tipton, and carbon fiber Tipton rods... I have G96, CLP, Break-Free, and a handful of others on hand, but I spend the least time cleaning and get the cleanest results using Hornady One Shot and Butch's bore shine on my bores, Hornady to clean action parts, and Hornady or Frog lube to slick them up.

Hornady and Frog Lube have completely changed my perspective about certain actions which I would have said 10yrs ago "like to run wet." I used to run my Benelli's and AR's almost dripping with Mobil 1. They run just as well today, with less gumming, using Frog Lube and One Shot.