An alternate way that does not involve automation: use the slice tool to cut up the audio, thereby turning your last word into a separate event. On Mac, hold option & command at the same time, and drag Analog Delay to the part you want to affect. This is known as adding "Event FX." You can add as many effects as you like to any section of audio. For example, in addition to Analog Delay, you can add reverb, EQ, or anything else you might want to that last word to get the sound you're after.