You can use those products, but I wouldn't recommend it. Why? 1) They are acidic. You might find out the cost of Borax and Bakling Soda or Soda Ash to counteract the pH drop and TA reduction negates any savings. On the other hand, if you have really high TA and the pH is also high and rising, it could work. 2) They take a long time to dissolve. Let's say you target 50 CYA. Every 10 FC you add via trichlor pucks will also add 6.4 CYA. To get to 50 CYA (82 FC), you'll need to add 204 ounces of pucks - that's almost 13 lbs.... 26 pucks... which will take weeks to dissolve. Assuming a loss of 3 FC per day, that's at least 27 days. Summer will be over before that!
Perhaps adding CYA to get to 30 initially, and then chlorinate with the powders until you hit your target CYA. As long as the bucket stays sealed, your dry chlorine leftovers will last for years.