I have found that the klean strip brand of enamel and lacquer thinners are too strong for model buillding purposes. The enamel thinner will sevearly weaken styrene plastics and turn them into a brittle mess with parts snapping and cracking at the slightest touch. The lacquer thinner will completely dissolve model plastic.
I recommend staying with enamel thinners formulated for model building as well as lacquer thinners formulated for model building. I've soaked plastic parts in Mr Color thinner without any adverse effects, and at the same time, I've done this test with Klean Strip Lacquer thinner, and the plastic was completely dissolved.
However, I do use Klean Strip lacquer thinner to clean tools such as my airbrush and such. The stuff just never touches my models.