Smeargle can work in different ways than Mew, Baton Passing Butterfly Dance, Gear Change, Shell Break, etc.
Spore works with Focus Sash.
Smeargle: @ Focus Sash
Spore
Butterfly Dance / Gear Change / Shell Break
Endeavor
Baton Pass
Sometimes using Endeavor on the switch in from Spore causes another switch (they expect priority like Extreme Speed coming next and don't risk losing their Pokemon), so you can Butterfly Dance as they switch out, then Baton Pass to safety.
It would be good to list some Baton Pass Special Attacker recipients, such as Porygon2 whom can safety take a hit, and benefit from Butterfly Dance.
Also Simple Pokemon benefit from this, especially Kokoromori whom can turn Assist Power into instant power after a Shell Break Pass (White Herb on Gorbyss).
+4 Special Attack, + 4 Speed, and the +4 Attack = 12 x 20 = 240 + 20 (original base power) = 260 x STAB = 390 Base Power from 1 Shell Break pass.
Also, keep in mind Huntail isn't so bad... It can also baton pass, and is less obvious than Gorbyss for doing so:
Huntail @ White Herb / Liechi Berry
~Shell Break
~Baton Pass
~Aqua Tail / Waterfall
~Return / Crunch / Substitute
Keep in mind Huntail/Gorbyss are likely to be low on HP as they go second on the turn they use Shell Break, so it is likely that with a Substitute or taking the hit alone will activate Liechi Berry, which can aid in Baton Passing. With White Herb being held by the recipient, you are taking away a risk that an Intimidate user was facing Huntail, or will switch into Huntail and use up White Herb. Also, a Liechi Berry boost is stronger than the recipient using Life Orb (50% to attack vs 30%), and doesn't cost precious HP per turn.