Second, the citrus, use orange oil rather than lemon as it is stronger and cleans better. My supplier is in St Petersburg but, there are many others.
http://www.citrusdepot.net
If the wood is over oiled or waxed as mine was, this much stronger first step cleaning will bring the wood back without sanding. My veneer is too thin to sand. Use paint thinner as a base, add oxiclean and oil soap. Scrub in and rinse. It may take a few scrubbings to get the wood back the way you like it. This worked well for me.