Is it possible to do this without using the default template rule? - on some
XML files there are hundreds of text nodes and just a few interesting ones.

So, redefine bult-in template rule as you did
<xsl:template match="text()"/>

and define templates for those you are interested
<xsl:template match="text()[some-expr-identifying-interest-text-node]">
...
</xsl:template>

--
Oleg Tkachenko
Multiconn International, Israel