While I wouldn't use the "state of grace" phraseology, I understand what you are talking about and will say, that's not just a Catholic belief but one in every church I've ever been in.
27 Wherefore whosoever shall eat this bread, and drink this cup of the Lord, unworthily, shall be guilty of the body and blood of the Lord.
28 But let a man examine himself, and so let him eat of that bread, and drink of that cup.
29 For he that eateth and drinketh unworthily, eateth and drinketh damnation to himself, not discerning the Lord's body.
The Catholic Church does not dispense Communion to those who are not baptized in their faith.... If you choose to receive fraudulently it is considered an imperfect sacrament. This is my understanding of my own life long faith. I have respect for other faiths and would not presume to “crash” their worship rituals for any reason. Least of all to enhance my own ego.