wood tonic hurts ?

I've been using Lemon Oil for many years on all of my wood (including speakers) and have had no problems (no darkening or other changes in the wood). I would recommend Lemon Oil on your wood furniture and appliances. It also smells very nice.

I have used "Howard Feed-N-Wax" with very good results. I first used it on a Monterey dining table from the 40-50's's that was is very poor condition and it worked so well that I use it on everything now, including speaker cabinets. Even on "light cherry wood", for example, it does not change/darken the color of the finish.

A second vote for Howard Feed-N-Wax. Just make sure that your cabinets are not sealed with polyurethane or epoxy finishs because then any wax or oil will slide right off.

I've been using a food grade mineral oil -- the same stuff I use on maple block surfaces -- very effective, safe and non-toxic when lips are pressed against the speakers.

The only thing I would caution is when dealing with veneer. Too much solvent based or even oil based treatment can damage the adhesive and cause the veneer to seperate from the cabinate. Fortunately this occured when trying to revive a worthless old table. Use enough, not too much.