Solumni explained the first part. :3
OK so Fling isn't all that viable in the first place. Many more moves can be used that aren't a significant damage drop, so I wouldn't use it at all. Plus, taking a turn to Recycle is not worth it as you could just launch off another attack and get more damage off altogether. Plus, you lose your valuable item slot (Life Orb, Choice Items, ect.).
If you are thinking about using it for Status, don't try that either. Again, the turn Recycling is not worth it as you could possibly get another Burn/Toxic off on what the opponent switches in (If they do). And again, the item slot is extremely critical as you will most likely be using a defensive Pokemon who will really miss it's lefties.
Hope I helped! :)