When you tackle the spokes you must resign yourself to a long spell of tedium if you want to do it properly. The back of the rim and hub is simple by comparison, and can be protected simply by a regular wipe with an oily rag (light oil or WD40), or a less frequent treatment with wax (not polish). Old fashioned hard wax will stay on best in this environment. On the outside edge of the rim, there's a zone behind the spokes and in front of the raised part of the rim, which is very hard to get at, apart from a little finger wrapped in a duster. Where the spokes cross over, even shoe laces don't fit, so you'll need a range of tools to do a whole wheel. Large brushes work well enough to remove real grime with soapy water, but I make every effort not to get them that soiled in the first place.
