Ah, superstition--close.
Actually nothing to debunk for centuries, as the first Christians did not believe as you do.
"For I received from the Lord that which I also delivered to you, that the Lord Jesus in the night in which He was betrayed took bread;Do it in remembrance of Jesus.
24 and when He had given thanks, He broke it, and said, "This is My body, which is for you; do this in remembrance of Me."
25 In the same way He took the cup also, after supper, saying, "This cup is the new covenant in My blood; do this, as often as you drink it, in remembrance of Me."
26 For as often as you eat this bread and drink the cup, you proclaim the Lord's death until He comes.
27 Therefore whoever eats the bread or drinks the cup of the Lord in an unworthy manner, shall be guilty of the body and the blood of the Lord.
28 But let a man examine himself, and so let him eat of the bread and drink of the cup," (1 Cor. 11:23-28).
That was His instruction.
It's pretty obvious that His disciples were not watching him tear a piece of His Body off and handing it to them.
It's metaphorical, but nevertheless, Catholicism is pretty certain of their ritual to the point that it became very dangerous for any that didn't buy into it and instead did communion the Biblical way:
"If anyone denies that in the sacrament of the most Holy Eucharist (communion wafer) are contained truly, really and substantially the body and blood together with the soul and divinity of our Lord Jesus Christ, and consequently the whole Christ, but says that He is in it only as a sign, or figure or force, let him be anathema." ) p.79, Canon 1.Anathema-To be damned and put to death
There are a bunch more 'anathemas' calling for death for those that don't believe as Catholicism does, but the above should suffice for now.
I did find something I had never seen before in my years of research into Catholicism. From The dignity of the priesthood by Liguori, p. 33
"...the power of the priest is the power of the divine person; for the transubstantiation of the bread requires as much power as the creation of the world. ...thus the priest may be called the creator of the Creator..."Amazing.
DO THIS is he important part of the sentence......in remembrance of me is why to "do this".
In John 6 He was talking to unbelieving Jews though His disciples were with Him at the synagogue.
Quite a difference in the audiences and the messages.
The disciples understood what He was saying in MML.
The Jews did not, not did some of His disciples, in John.
Paul understood the content of the message as well as noted in his writing to the church at Corinth.