Can Clockspinning from Time Spiral be used to remove infect or poison counters?
The Magic comprehensive rules state that:


  110.1. A permanent is a card or token on the battlefield. A permanent remains on the battlefield indefinitely. A card or token becomes a permanent as it enters the battlefield and it stops being a permanent as it's moved to another zone by an effect or rule.


As a player is neither a card nor a token, and a player is certainly not on the battlefield, Clockspinning can not target a player and thus can not be used to remove poison counters. It can, of course, be used to remove -1/-1 counters on creatures that was caused by infect damage.