My experience is if his truck is rusty as it sounds he will need sand. I've tried plastic and soda. It just plain won't get the rusty stuff clean.
I buy my sand at the local concrete mixing place for $.25 per 50lb bag. I use Fine but they have Extra fine and medium. It is "sized" and works very well.... and its also the choice of a couple professional's I know that also do soda and other stuff. They all agree soda and plastic is good for getting off paint but not for RUST....... just my .02


1937 Chevy Pickup
In the Gallery
1952 Chevy Panel
In the Gallery
More photos
1950 Chevy Coupe
Pictures!

I'd rather walk and carry a Chevy hub cap than ride in a Ferd.
I can explain it to you, but I can't understand it for you smile