Be Careful What You Witch For - S2-E22
Other mistake: Phoebe says to the genie "you've been stuck in the bottle for 200 years?" Later the genie says he will be an unwelcome house guest and not put the CD's back in their case. If he was in the bottle for 200 years how would he know of CD's?
Answer: That was a mistake in the series.
Also, the episode is called 'Babies First Demon' and this alone tells us that it's Wyatt's first time in the field (so to speak) and as the sisters say, they've done a good job of clearing up their own magical messes so far. Nobody really knows how advanced Wyatt's powers are, or will become. That's why the cleaners appear, to nip things in the bud. The Cleaners didn't want to chance that the sisters could clean Wyatt's magic up, just incase they couldn't. Therefore intervening themselves, just in case.