How do I clean knotty pine walls and kitchen cabinets?

Good morning Myrna. Have you tried Murphy's Oil Soap?

If really bad try TSP.

TSP if really grimy. Murphy's Oil Soap for general cleaning.

I use TSP substitute in a spray bottle mixed with water and a rag. Cleans grease and grime right off with zero effort.

Hello, I tend to use a soapy water Dawn solution for mild weekly cleaning and Murphy’s oil soap for more moderete cleaning jobs. Murphy's oil soap is an excellent all purpose wood cleaner.

http://homeguides.sfgate.com/clean-kitchen-cabinets-using-murphy-soap-104703.html

http://www.murphyoilsoap.com/home-care/murphy-oil-soap-uses ;

Baking soda & peroxide scrubbed with a toothbrush.