It the cli you can. In the web GUI you can't.
In the GUI, even though it starts powering down all your SP, only 1/104 is powered down per week in practice. So you can stop it after a few weeks.
While the process is ongoing, the portion that isn't powered down yet is unaffected (still counts toward voting power, still earns more Steem, etc.)
Thanks again! I really like the system so far, though I don`t understand everything yet. I keep upvoting stuff but my Steem Power keeps increasing. Am I not supposed to pay the guys something when I upvote them? I would like to upvote you as well
Anyway, reading the whitepaper now...
Found the answer to my question on page 40:
"Steem bypasses micropayments completely because when a user upvotes a post it is the
community that pays the bill. The same amount of money will be spent whether the user
upvotes a post or not and the funds will not come from the voter."