Tri-chlor in the skimmer is a 'NO-NO" IMO, A teathered floater is a much better alternative, but let's face it - exclusive use of tri-chlor is an invite for chem problems. The trouble with pucks in the skimmer is the damage they do to the plumbing and (if you have a liner pool) the area around the skimmer mouth when the system is off. I'm wicked tired now or I'd tell you a way to use the tabs safely - the only problem is that it be at least as much work as just using bleach to chlorinate your pool.
(this is 'hell week' for pool dudes, everyone wants their pool for Mem day, even though it's probably going to rain )

If you want more info, I'll get back to you this weekend -