Draw from implied imagery using words that may seem unusual in the situation.
Consider...
"flopping" (the towel)
I stepped out of the shower, grabbed the towel without looking, then started flopping it around my body.
From the verb: flop
The advantage of "flopping" is its phonetic similarity to "sloppy", the idea you are going for.
"dabbing" (oneself)
From the verb: dab
I dabbed at my soaking wet body while glued to the TV.
"Dabbing" is not in itself a "sloppy" work, but as a means of drying oneself with a towel—that would likely describe an effort that is sloppy by implication.
"throwing on (the towel) like a cape"
Exiting the water and throwing on his towel like a cape, he darted inland.
From the verbal phrase: throw on
This is a little farther from your idea, but it still works and is a usable example of what you can do.
Likewise, consider...