His Shark sword wouldn't have made much difference there.But Madara did absorb it :| the sand only acts as a defense by its self all attacks are chakra infused. Not to mention kisame can create a whole lake if he wanted to which would made all gaara sand he could potentially make gone. Once his sand get wet he has nothing
Kisame was trying to escape not fight. He didn't have his shark sword and was not at full strength.