Um, so:
https://www.bg-wiki.com/bg/Shockwave
I don't know if anyone ever used to use this, but it seems fairly accurate these days and the duration is laughably long. Honestly I only did about 10 WSs before I got bored of it and warped because I was sitting around waiting forever for these damned sheep to wake up.
The text on the page might be confusing, but what I mean is that I can use the same WS on multiple sheep (at the same time) and they will wake up at different times, up to 50% of the longest one's duration apart. The longest duration 300TP Sleep I had was 6 minutes.