Clean Audio Scrubber/Freezer

So I've been working for quite a while now on developing some sort of audio scrubber that will allow me to cleanly move back and forth through an audio clip, and naturally freeze the audio wherever I stop. I have found many fantastic tutorials for granular synths on youtube and on this forum, but unfortunately no matter how I tune them my samples always end up sounding super phasy and nothing like the original.

Recently while scrolling through tiktok I saw someone using an audio scrubber to mess around with the playback of a video clip, and I noticed that the scrubbing and the freezing of the audio was super clean and exactly what I am aiming for. The app I was seeing is called AudioStretch (found here: https://www.audiostretch.com/ ).

Would anyone be able to point me in the right direction as to how I could begin creating something like this in max? What is the key to a clean scrubber/freezer? Cheers!