According to Barry Miles’ Zappa biography, Tina Turner was so impressed with a rough cut of the song, she volunteered herself and her backup singers to sing the “raising my lonely dental floss” backups on the song. Afterwards, Tina called her then-husband Ike Turner into the studio to listen. According to Miles, Ike listened for about a minute, declared “What the hell is this shit?”, and left.
“I’d like to see Christ come back and crush the spirit of hate and make men put down their guns. I’d also like another hit single.”
As a bonus, here’s a top rate version of her and Ike with “Proud Mary”: