Whether they're lacquered or not is the problem. The decals themselves are water soluble- remember soaking them in water before removing them from the sheet?
I'd be wary of using any solvent on painted models. The decals themselves are very fragile, so solvent isn't a good idea if you want to reuse them, and I would worry about the solvent distorting the paint (though I'm confident that this "solvent" is mostly water).