I think Jesus did.
“Whatever goes into a person from outside cannot defile him”: this is a categorical statement. “Whatever” is PAN in Greek, meaning ‘all things’. All things that enter (or, whatsoever enters) into a man from the outside, cannot make him unclean. The statement is meant to mean the opposite of: “What comes out of a person is what defiles him.”
The issue is direction. What comes from outside into man does not make him unclean, but what starts inside man, and goes out, that is the real issue.
What goes into man is about food and drinks. The discussion started with Jesus being criticized for his disciples not washing their hands. Jewish law assumed that not washing hands could make people unclean as you never knew what you might have touched. Jesus, however, makes the discussion broader. He does not focus on whether people should wash their hands or not - he says that dirty hands, or anything that enters into the stomach, is unimportant in regard to defilement. It cannot impact our relationship with God because it is about the stomach, not about the heart.
The heart is the source of sin, Jesus says. The bad ideas and attitudes of our heart, they defile us. Not what we touch or eat. No love, that defiles us.
Mark thought that this concept was so important, that he interjected a few words. In verse 19 he says: ‘Thus he declared all foods clean”. In Jewish society, this was a radical conclusion. But even today, some Christians who are much in favor of the Jewish lifestyle, cannot accept this idea. They prefer to see Jesus as one who abided by all Jewish laws.
So they suggest that the stament: ‘Thus he declared all foods clean", should be read differently. Literally the words say, ‘cleaning all foods’. Most bible translators believe this to mean that Mark suggests that Jesus here declared all food clean. Some, however, say that this cannot be, and that the words refer to the immediate words before it: “whatever goes into a man from the outside cannot defile him since it […] enters his stomach, and so passes on.” The Greek term refers to the latrine.
What is this? By the “passing on” the food is cleansed? This seems too strange to be taken seriously, but some people will do anything to avoid the idea that Jesus simply said: eat whatever you like, eat pork if you want, for God it does not matter.
For the early Christians from Jewish and non-Jewish backgrounds, this issue was incredibly important. The early church had as a focal point of its worshipful life, the table-fellowship of all believers. Food could not be allowed to separate people and the Jewish followers of Jesus therefore had to understand that to eat or not to eat was not important at all compared to mutual love and community.
For Jesus and the apostles it was unthinkable that for the sake of Jewish habits, the unity of the one Body of Christ could be broken. Hence Jesus’ focus on matters of the heart instead of whether we wash our hands or not. Superficial cultural matters like what we eat or drink - and we can add many things to this list - must never be allowed to divide Christians into groups that cannot enjoy close relationships.
That this is the correct reading of these words of Jesus is confirmed by how Peter and Paul often write about similar food-related matters. Think of Peter who was told in a dream to eat all sorts of 'impure' animals, before God send him into the home of the Roman soldier Cornelius (Acts 10).