Question

Rest
Sleep-talk
Roar/whirlwind/circle throw/dragon tail( is there anything else?)

Also, what happens if you use sleeptalk rest?

Answer 1

Sleeptalk rest fails
But for your main question the quickest Pokemon that can abuse it ate darmanitan and suicine.
Suicine is the only Pokemon capable of pulling it off.
Giratina is an Ubers altternative which works very well Source

Comments

the moveset searcher isnt fully updated but use that in future