My favorite thing to do is mock the songs while I am singing them by inserting alternate words or clearly pronouncing the rediculously shortened words such as "pow'r" and "heav'n".
Song 32:
...From house to house, from door to door, Jehovah's turd we spread. From town to town and farm to farm, Jehovahs sheep are bled...
Song 29:
...Then forward, you Witnesses, ever wrong of heart! Rejoice that in God's work you too may have to fart!
Just soften the consonants and they'll never hear it...
Song 15:
...Live for the day when you'll say: "Life without end, I'll pass!"
My favorite line of all the songs: "We will not be de-terred." You got that right.