Painting over many stains? Going to be painting a few rooms surrounded by my house just...

Going to be painting a few rooms surrounded by my house just call for a simplistic way of removing or covering up the stains. All the stains, due to neglect them have set surrounded by ranging from handprints and writing on walls (marker contained by various colors, pencil , pen, and crayons)

I hold heard that Kilz is the best for priming / covering up set contained by hard to capture stains.
Answers:    You heard it right. I can not grant you a better solution. You might want to use two coats of paint.
Use a product called TSB. (wear gloves, its caustic) consequently a high power primer/sealer