G'day Soozansings,
Look at it like this.
The Camino is not a walk through an alien environment but a celebration of many things. Of life, of Spanish culture, of the Spanish countryside, of the creation, of nature, what have you.
You become a part of it, in effect you are not an alien or a visitor, but you become Spanish. Now, it's said that all the Spanish are Catholics, even the atheists are Catholics...
On a more serious vein, as an Anglican I have no personal issues sharing communion in a Catholic Church. Neither does my wife. My sister in law, who travelled with us in Spain, is a Salvationist, and after some hesitation she came to take the communion as well. I haven't met too many priests who seem to have an issue with it either.
It's really a matter of personal conviction. The practice of communion is a specific inclusive command to the church as the fellowship and body of believers rather than something exclusive to a particular denomination, and priests who my wife has spoken to on this very issue support this view.
I hope this doesn't infringe Site rules.
De Colores
Bogong