Trichlor pucks are very acidic so if they slowly dissolved then the acidity might build up and that could damage The Liquidator, especially if it had any metal exposed to that water. Using pucks would also add to Cyanuric Acid (CYA) level. If that's what you want to do (i.e. increase CYA level), then using a floating feeder would be better, though even then you want to make sure such feeders don't "park" themselves near metal in the pool. I had that happen in my pool and it caused rusting of the metal mounts for the stainless steel rails I have in the pool.
To add CYA to a pool, it's usually easier to either use pure CYA hanging it in a sock or panty hose over a return flow (takes a couple of days to dissolve) or use Dichlor (which dissolves quickly) as your source of chlorine for a while.
Richard