Because the original poster didn't specify the format, I have to answer for every format. Note that I think a Pokemon used less than 2.1% is not good and was probably only used by trolls, so if a format has no resto chesto Pokemon used more than 2.1%, I'll just write "none".
Anything Goes Singles: none
Doubles Ubers: none
Conclusion: Resto chesto strategies are pretty bad. You're much better off sticking to 1/2 healing moves like softboiled and roost. If you really want to use rest, then it should be used along with sleep talk and not chesto berry.
There were so many sources that I was too lazy to list them all. If you want to know where I got information on a particular format, I can link you to it.