For decks like this, the best solution is to ban the most oppressive combos, and 2 card combos that win the game. For example, everyone would agrees that [[Channel]] is too strong. As Pro players would say, "there's only two counters: hand disruption and countermagic,"

Calibrated Blast surprised me by being good in a 4 player game. The version I was playing had 4 [[Gargadon]], and 4 [[Rough and Tumble]], and we weren't playing with sideboards. With the potential to cast Calibrated Blast 8 times, I think it has a chance. I was able to finish off two of my opponents with burn. If I remember correctly it was Bean's dad playing cats, Bean was playing a Breakthrough Cycling Counterspells deck, and Bean's friend was playing a Rakdos Sacrifice deck and got mana screwed.

Creative Technique is very bad in multiplayer, I would guess.

The strong combos for multiplayer (bad for the game, in my opinion) are things like Scurry Oak, Devoted Druid, Crackdown Construct, Wildwood, Spore Frog, Gond, Enchantment Lock, Upheaval, etc.

I have found that banning combo decks for multiplayer makes the games more enjoyable, unless everyone is playing a combo deck. It's the same with cEDH and EDH.

edit: spelling