I used to do that, but I find that the hash marks tend to visually “smother” the text they surround, particularly when it is short, as in your example. Try putting several short substitutions like that in a row:

s#foo#bar#g, s#bar#baz#g for @line;
$line[0] =~ s#baz#quux#g;
$line[1] =~ s#qoox#frobble#g;
s#firble#flar#g, s#fooz#bish#g for @line;
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Most people's eyes will glaze over. I know mine do.