Lacquer thinner used to contain large amounts of aromatic hydrocarbons, benzene in particular was one of the big bad ones. Lacquer thinner was a great solvent or even plastic welding "adhesive" but one of the worst solvents the average person could expose themselves to in terms of health. In the early silk screening,art world it was blamed for the insane amounts of bone marrow problems, leukemia's, etc.. Those folks were not careful at all with it, it devastated a generation and their kids. Literally meant to make liquid plastic flow better and dissolve it from things you do not want the plastic on.
Absolutely keep it away from children, brain death in a can, smaller the body smaller the exposure amount before marrow issues.
Supposedly the new or current lacquer thinners have had the amounts of bad chemicals in them reduced and are not as bad for a person to inhale, or have contact with. Not sure that I would be willing to believe that.
Never seen a carb that needed a solvent beyond chemically pure acetone or starting fluid ether. Granted the ether will probably have a small amount of toluene in it as upper cylinder lubricant, I would still prefer it to a can of lacquer thinner. Ether, WD40 and acetone are not good for a person either, so use as little as possible in a well ventilated area away from any ignition sources. Nobody wants a case of the ether craps or the headache.
Usually I just use WD40, and gloves. Hands are messed up enough already.