Yep, if you aren't using Mandibuzz herself to clean hazards, Excadrill is your best bet as a spinner. He can also act as check against Gengar (if you are using Physical Defensive Mandibuzz with investment and/or Assault Vest. Excadrill has obviously great type synergy with Mandibuzz, what with Rock / Electric resistance / immunity. Excadrill is just great atm so yeah, it seems solid.
The one problem I have is the lack of some resists (especially Fighting one). Some mons, like Lucario or Garchomp, are just pain in the ass for them, so you'll need something like Landorus-T (another Ice / Water weakness, slow), Gliscor (same), Gourgheist (which I find a bit lacking) or something else obviously (I'll have to try the mummy). To keep it clear, I find it limits a bit my flexibility when it comes to team-building.
But that doesn't mean that those two are just great and they are far from being set-up fodders (Excadrill has, well, a gargantuan attack while no one wants to set-up on a mon with Whirlwind AND Foul Play AND Taunt AND Knock off AND U-Turn. Come on).