Draw from implied imagery using words that may seem unusual in the situation.

*Consider...*

# "slopping" (oneself with a towel)

> Slopping myself with the towel, I gazed out the window at the commotion below.

From the verb: *slop*

Since "sloppy" is the description you are going for, simply use "slop" as your verb.

# "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...

# slapping, smacking, mopping, brushing, flapping, rolling