I can't speak for MWSMITH2, but I don't use any at all, it adds stabilizer, then you have to use more chlorine to have it be effective - it snowballs, only add stabilizer when the CYA level drops, teh ONLY way CYA will leave your pool is through pumping it out (backwash/drain/Leak), otherwise it should remain stable pretty much all year.
As for pucks, the only time you will see pucks in my pool is when I go away for over a week because the pucks will insure keeping the Cl levels up.