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.
How long, LORD, must I call for help, but you do not listen?
Or cry out to you, “Violence!” but you do not save?
Why do you make me look at injustice?
Why do you tolerate wrongdoing?...
Therefore the law is paralyzed, and justice never prevails....