Glad to know we're on the same page with this
To continue the "is it safe" discussion, consider that at 20% concentration (enough to actually make a difference, toluene or xylene, as solvents, offer zero lubrication, and significantly degrade the lubricity of the remaining gasoline. This has obviously negative effects on things like fuel pumps, but is also particularly bad for the upper cylinder area, which relies partly on the fuel to lubricate the rings, and the rest on oil. They will also eat away at the fuel system. Adding a strong solvent to the mix washes the oil film from the cylinder walls, and you will experience increased cylinder bore and ring wear. Whatever small amount that makes it past the rings will degrade the oil, and cause increased bearing wear, also necessitating more frequent oil changes to try to combat this effect (added cost).
Both of these chemicals are also incredibly toxic to handle, and dispose of their containers.
Some will point out that, yes, Formula 1 cars used to run almost straight toluene, and that's true. Their motors also only had to last one race, and it was human health concerns that caused F1 to ban the fuel.
Lobo, I'm not sure where you're getting your information, but substituting solvent for fuel on a street car that doesn't get its engine rebuilt every few races is not a good idea, nor is handling this stuff on a regular basis.
To put this into practicality, last time I saw toluene at Home Depot, it was about $10/ gallon. Substituting 20% toluene (at $10/gal) with 80% premium unleaded (call it $3/gal) yields an overall fuel cost of $4.40/ gal. You can buy 100 octane race fuel for that price, and that is a high quality, safe fuel (both for your health and the health of your motor).