A local gun store owner told me that Break Free CLP is not a good lube and will acctually harm plastic and wood. I didn't buy it but he is older and said he has seen this. From what I read here Break Free CLP is 100% safe and can even be used to whip wood down.

I use CLP only, never got any on wood so dont know, as far as plastic, I always wipe the outside of my guns with Silicone rag after cleaning and handling.  Now GUN SCRUBBER will melt plastic, I learned that one the hard way, disolved some Ruger MKII grips in a matter of seconds. With any solvents or cleaners or lubes jus watch where ya put it and dont make a mess, wipe off outside with silicone or atleast a dry clean cotton rag and youll be fine.

Might depend on the type of plastic, but I doubt it is harmful. Many use it to wipe down their plastic stocks, and it does come in a plastic bottle after all.

I started using Break Free in 1989 and continued to use it up until the fall of 2002.Never had a problem with Break Free on polymers...even with the old formula which used chlorinated solvents in the mix.
Although Break Free will darken wood if its allowed to sit and soak the wood...but so will most other oils.It does seem to pull BLO finishes a bit if allowed to soak in.
But as far as damaging polymers or wood finishes like True-oil or Tung etc. Ive never had a problem.
FP-10 and TW-25B are also safe for polymers,oil finishes and paint in my experience.Just as they are advertised.
Raymond

Most "oils" bad for wood the weaken the fibers. The finish on modem day stocks can but up with a lot, agin not a good idea to soak your wood stock in a dino oil its not good for the wood. it will "soften" the wood.