Walnut seems to typically dry pretty well without a lot of checking but the ends of almost any wood will want to split when drying. Anchorseal is supposed to be a really good product but you wont find that at the stores you mentioned. I just bought some anchorseal but before I had that, I used regular latex house paint-3 good coats just after it was cut and that seemed to do the job, except for the pith in one board.
Lowe's and HD often have gallons of mis-mixed paint for a couple of dollars...or maybe you have some old paint cans in the basement like most of us do.
Either way good luck with it.
Edit-I'm assuming your checking is on the ends of the boards. If the checks are on the surface and not at the knots then you might be drying it too fast? Somebody else jump in if this doesn't sound right.
Last edited by ARECHER; 07-03-2009 at 11:02 PM.