No. From the FAQ:
...if you use an ability to make one monster disappear, you cannot claim
levels and/or Treasures for beating it (depending on the method used)
unless you can then kill or defeat all the remaining monsters. You
cannot, for instance, use your Wizard to charm one monster and take
its Treasures before fighting the rest. Combat isn't over until ...
This should help you.
Q. The Wand of Dowsing doesn't say "Usable once only," but I have to discard it after I use it. Can I treat it like a one-shot (play it from my hand rather than the table, or play it during combat)?
A. The clear intent is that this is a one-shot card, even though it lacks the magical "Usable once only" language, and ...