I am finding this strange they have a special sink so Jesus doesn't go through the sewer but He goes through the sewer when he is expelled from our bodies.From Catholic answers:
The Catholic Church teaches that after the valid words of institution by an ordained priest, Christ is really, truly, and substantially present in every discernible particle of what appears to be bread and wine. ...
For this reason, every parish sacristy has a special sink called a sacrarium that empties directly into the ground rather than into the sewer system, so that any remaining particles are properly buried when the vessels are washed. These practices are a sign of tremendous respect for Our Lord in the Blessed Sacrament. ...
Catholics believe that because the Eucharist is Jesus Christ—the second person of the Blessed Trinity, fully human and fully divine—it is due reverence and adoration.
I copied this from another thread.