...Because I'd remembered posting that I used Armour All on everything. I read recently in one of my build books (Dan Erlwyn's) to never use anything with an oily residue on the guitar body or parts. This includes furniture polish, and probably most non-specialized waxes.

The reason he states is it can cause problems if you ever require certain future repairs or maintenance. (He was a little unspecific on exactly what.)

Approved substances are naptha (as someone previously stated), breath, spit (on your own guitar), or specialized guitar cleaners. Lemon oil is fine on fingerboards, but should be used sparingly. (I will edit more in if necessary, I don't have the book in front of me.)

I'm not sure how important it really is, depending on the circumstances. My father has used Lemon Pledge on his ES335 with nary a problem for as long as I am old (and that's getting pretty old! :p) However, I think I will alter my own approach to cleaning hereafter.

Ironically, this info was in chapter 1, 'How to clean a guitar', but I skipped that chapter. What's there to know?? lol!