grammar - Two を in a single sentence - how to understand it?

In the book I'm reading (「キッチン」 by 吉本{よしもと}ばなな) I have found the following sentence:

うしろで雄一がぞうきんを手に床をふいてくれていた。

I guess it can be translated to something like (sorry for a quite literal translation): "Behind (me) Yuuichi was wiping the floor with a cloth using his hands".

This sentence has two を. One of them (床をふいてくれていた) I understand as marking the direct object (floor) of the verb (wipe).

I cannot understand what the other を is doing there (ぞうきんを). What meaning does it have? What grammatical pattern is used in here?

Answer

You usually can't have two をs in one clause, so when you see one, most commonly one of the following is true:

1. 
   

   It's part of a 〜を〜に（して） construction in which して is left out.

   
   

   
   

   AをBに　→　AをBに（して）

   
   

   
   

   You can recognize this one by the distinctive 〜を〜に pattern, often with a comma.

   
   


2. 
   
   

   A repeated verb has been left out ("backward gapping"):

   
   

   
   

   XがAを、そしてYがBを買った　→　XがAを(買い)、そしてYがBを買った

   
   

   
   

   Unlike English, in Japanese the last verb is retained rather than the first.

   
   


3. 
   

   The を links to a verb in a subordinate clause.

   
   

   
   

   Aを [ BをCして ] Dする

   
   
   

   
   

   If you see two をs in a row like this and they don't seem to suggest the same verb is coming up, it's usually a signal that the speaker has started a subordinate clause. Each を links to a different verb.

   
   

In this case, I suppose it's probably #1:

うしろで雄一が　ぞうきんを　手に(して）　床をふいてくれていた。

Yuuichi was wiping the floor with a cloth in his hand.