i've experienced foot-washing several times. never in a church service - it is quite meaningful when in a small group with people you feel close to. once was in a youth group, once in a small Bible study group, another time we washed one another's hands rather than feet. it really felt humbling and intimate - took a lot of trust - both being the washer and the washee. i think it would be sort of weird with strangers or people you don't know well.
"Tell your heart that the fear of suffering is worse than the suffering itself... And that no heart has ever suffered when it goes in search of its dreams, because every second of the search is a second's encounter with God and with eternity." - Paulo Coelho