I haven't tried it, but it doesn't sound like it would hurt to try at least once. It's seems like it could be a rather inexpensive "product" to add to a regimen in addition to having tea to drink if you didn't like it in your hair. I wonder if you did any of them often enough if it would change hair color?
I think I had read somewhere about using chammomile to sort of help lighten hair over time. I would guess that any of the sort of brown teas may help enrich brown hair or maybe darken blondish hair based on that?