You just quoted the instructions for turning the keypad press tone on/off, which obviously has absolutely nothing to do with squelch tail.
Assuming you were trying to quote the instructions for turning the Disconnect Tone (End Code) on/off (page 57 of the PRO-160 manual, page 66 of the PRO-162 manual), that also has absolutely nothing to do with squelch tails. Disconnect Tone (End Code) applies only to Motorola trunked systems and indicates the end of transmission so the scanner can return to the control channel quicker than waiting for the squelch to close after a talkgroup transmission on a voice channel.
"Squelch tail" refers to the burst of static at the end of a transmission on a conventional, analog frequency. Nothing you've posted has any relation to that whatsoever. The only way to alleviate squelch tail is to program a PL/DPL, and hope whoever you are listening to has reverse burst enabled in their radio programming.