New word for me: "Lappen", but ok. But not sure I get it. The character is to clean the garage to find the rag, or they pretend they can't find the rag when asked to clean the garage?

The Lappen/rag is the husband. Like an "old rag".

The question was for an actual rag, but the reply was pointing to the old/lazy hubs.

Ah! I see. Thanks!