Poo out a sink is possible even with a macerator unit with the right blockage in the right place!
My first house in france had a waste system nobody really understood and it had macerator toilets, one day we flushed the loo and the results came flooding out up out the rainwater drains outside. Much probing and documenting later, we found out the whole system had no tank or filtering and everything just commoned right next to the house in a underground system with no access covers and just exited in a dirt track lane next to our property, that the farmer had ran over the end of with his tractor and blocked solid. 5k of micro waste filtration later and removal of the macerators, and all fixed...
In the uk you absolutely have to follow the building regs too, and its all laid out for you in advance. Id go with a physical vent personally myself because its less to go wrong but thats just me.
My first house in france had a waste system nobody really understood and it had macerator toilets, one day we flushed the loo and the results came flooding out up out the rainwater drains outside. Much probing and documenting later, we found out the whole system had no tank or filtering and everything just commoned right next to the house in a underground system with no access covers and just exited in a dirt track lane next to our property, that the farmer had ran over the end of with his tractor and blocked solid. 5k of micro waste filtration later and removal of the macerators, and all fixed...
In the uk you absolutely have to follow the building regs too, and its all laid out for you in advance. Id go with a physical vent personally myself because its less to go wrong but thats just me.