In the many excellent songwriting books by Pat Pattinson he points out that songs can get away with all sorts of false rhymes which the listener readily accepts.

I heard a pop song only the other day that rhymed "on" with "long" and the only reason I even noticed the false rhyme was because the lines themselves had good lyrics.

As songs are heard, not read, our ears usually don't notice or don't care. The example above - rhyming "bottle" with "swallow" is a good case in point.

The only thing that does bother me is when the rhyme is identical (in which case it can't really be said to be a rhyme). This rarely occurs, but it does occur in Ewan MacColl's 'Sweet Thames Flow Softly', in which the word 'standing' is rhymed with 'understanding'. That always mildly annoys me.