First off, I'm glad Kirby and King Dedede cannot drop through platforms while inhaling. Don't give Sakurai any ideas. If King K. Rool is using his Blunderbuss on the platform to try to catch any jumps or get up options, your best option would be to do a get up attack. The taller the character, the easier it should be for them to hit King K. Rool when he's using his B special. If he's out of range and you get sucked in anyway, and he always does this, then jumping up from the ledge might be a better option if he's not on the platform. If your character has a projectile that causes flinching or knockback, then you could attempt using that. Never just get up or try to roll past him when he's using his B special, though. On the topic of his Blunderbuss, it doesn't make sense that he can suck up the cannonball and fire it again, since in DKC2, throwing his cannonball back into his Blunderbuss would cause him to blow up. I wish they stayed true with that.