There is a technique to it, but it is easily learned and well worth the effort. If you clean a dirty tool like this, and then wax it, it will look wonderful, without any loss of patina. What about steel wool you ask. Steel wool is one of the most abused materials associated with antiques and far more antiques are damaged than improved by its use. A very fine steel wool ,0000, very gently applied with a generous lubrication of wax, can be used to clean dirty tools, but it is taking the easy way out and should never be used on anything rare or valuable.
Linseed oil is another old favorite that has lost favor in recent years.
Even museums used to use linseed oil on wood surfaces. Trouble is that it darkens with age and many museum pieces that were periodically oiled for years are not almost black. In general, you should not need any more than wax. Some wooden planes, for example, will be so dry and checked that it does make sense to give them one generous application of linseed oil. Planes found in barns often fit this description.