Steering Box Flush For Power Steering Issues?

[fireball]

From all the things I've seen on the power steering problems people have had with their trucks has anyone had any luck taking the steering box apart,cleaning and flushing out?My 99 Silverado is still not giving power assist both ways and most people have cured their steering woes by replacing the box,I was just wondering if it is a big job to take one apart and clean it out.