#!/bin/sh
USERNAME="username"
PASSWORD="password"
HOSTNAME="1.2.3.4"
while true ; do
        echo "show full processlist" | mysql -u$USERNAME -p$PASSWORD -h$HOSTNAME | grep -i -e temp -e tmp
        sleep 0.1
        echo -ne "."
done

# Use this to track queries in MySQL which are creating temporary tables.
# This might not catch everything, but it'll catch the worse offenders.
# Much love.
# Cal xoxo