Wall Hung Duravit Clog-Plunger doesn't fit/Snake is useless. Is there a special tool?

[1939house]

We have a Duravit Starck 3 Wall Hung Toilet that has always been tempermental. Can't get a seal on the mouth of the plunger because of the bend in the toilet and the snake through the toilet or through the clean-out isn't doing anything.

Does anyone know a trick with these or do they make a special plunger for these euro designs? We're stupidly installing another one next week. It was free but I'm sure the trips from the plumber will more than make up from that.

Any input is appreciated. Thanks in advance.

[Terry]

Your standard rubber plunger with the end that pulls out is the best.
Reach in and pull out the end, this narrows down to 2" and fits into the bottom of the bowl.

Small movements are best. Moving the punger up and down, maybe an inch or two on the up and down strokes and then slightly pull up to allow the suction to pull the waste down.

Keeping some water in the bowl to seal around the rubber plunger helps.