From the WD-40 page
"The catchall phrase "Stoddard Solvent” is no longer adequate to tell the proper story.
<nobr>WD-40</nobr>
does indeed have 50% mineral spirits, but they are refined and purified
for specific characteristics needed to meet today’s performance,
regulatory, and safety requirements."
Then there's Naphtha and distillates and stuff, all pretty easy to find online.
The MSDS for Ballistsoil...
Ballistol contains medicinal grade mineral oil, alkaline salts of oleic acid, several alcohols, Benzyl Acetate and an oil
from vegetal seeds. The mineral oil is unchlorinated and conforms to the specifications of US Pharmacopeia XX.
Volatile Organic Components (VOCs)
As an aerosol Ballistol contains 33.8% VOCs. As a non-aerosol it contains 5.3% VOCs
So, yea, the bulk of what's doing the work after the lighter stuff evaporates off in both cases is mineral oil.