Despite what its description says, Clearing Mist actually follows the exact same formula as Tumble Plant. I tried the two moves out using Kosuzu on wild Byakuren Puppets in the Hakurei Cave (neutral to both), and then against Yuki puppets in Makai (resists both). Not the most scientific of tests, but if there was a big difference in power it would show up here, especially against Bya. Both moves did pretty much identical damage to both puppets.
I also tried it out with a Lv 70 Suwako against a handful of different Steel-weak Lv 70 Wilds - Chen took ~70% from it, whereas PMarisa and SIku (same cost, different defences) were easily OHKO'd. So yeah, the move should work out quite well regardless of who is using it.