Since it's worth repeating, DO NOT USE ORANGE OIL on a guitar unless it's just orange scented mineral oil. There is a degreasing oil made from oranges called D'limonene that will eat away paint and adhesives. Check the ingredients before putting anything on your instrument.
Yes, they use the same ingredient in some of the "safe" paint strippers. Also in a hand cleaner product. I have some at home that I clean my hands with after painting or varnishing. It works good for that.
As a paint stripper, it's not very good. Won't touch a factory poly finish, but then, nothing much will. Works, although very slowly, on alkyd paints and varnishes.
Mineral oil is safe. Alcohol will dissolve shellac and lacquer finishes but won't touch oil finishes, or varnish or factory poly finishes. Alcohol will dissolve the nitrocellulose pickguards, the old vintage tortoiseshell ones and the nitro reproductions. I know, because I accidentally got some on mine. I caught it right away and was able to polish out the smudge mark.
Paint thinner, like Varsol, is safe on all the finishes. So is naptha. They might not be all that safe to use at home though. The fumes are not good for you and there is a risk of fire. Naptha is more flammable than paint thinner. You have to watch for sparks with naptha. That's what lighter fluid in Zippo lighters is. It's a great de-greaser though and also will dissolve old wax.
Yes, you probably shouldn't fool around with this stuff unless you know more about it.
Buy the products sold in the music stores if you're worried. Then, if anything goes wrong, you have soimeone to sue.