Continuity mistake: When the Charmed Ones decide to try to vanquish Cole, Paige says that the newest potions they mixed should work, since they're "at least as strong as the ones [they] used on the Source." But they never used any potions that had an effect on the Source. (00:34:50)
Continuity mistake: Watch Paige's right shoulder throughout this episode. Every once and a while you can see her black bra strap disappear, reappear, and disappear again between shots. (00:24:30)
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.