drenched to the skin
To be completely soaked with water—usually rain—through one's clothes. Come in out of that rain! Oh, you're drenched to the skin, you'll catch cold if you aren't careful!
drench in
To cover or saturate with something (typically a liquid). A noun or pronoun can be used between "drench" and "in." You can always count on Bill to drench his pancakes in syrup.
drench someone or something in something
and drench someone or something with somethingto soak someone or something in something. A sudden summer shower drenched them in sheets of rain. My raincoat was drenched with droplets from the foggy night air.