The most common and most likely answer to this crossword clue is the 7 letter word NAPKINS
I've seen this crossword clue in The Daily Telegraph
N
A
P
K
I
N
S
Buddy explains!
The straight part
We know that "They roll up and after opening up they clean up" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case they roll up and after opening up they clean up = napkins.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does NAPKINS mean?
NAPKINS noun- A serviette; a (usually rectangular) piece of cloth or paper used at the table for wiping the mouth and hands for cleanliness while eating.
- A nappy (UK), a diaper (American).
- A small scarf worn on the head by Christian women (chiefly Roman Catholic and Eastern Orthodox) when entering a church, as a token of modesty.
- A sanitary napkin.