Formal Reflexive Commands

[Hombre-Araña]

What pronoun does one use when commanding someone in the third-person (whether singular or plural) with a reflexive verb?
I know that in second-person, tú, you use the pronoun te:
Lávate!
But for Usted and Ustedes...?

I'm not sure when I would ever command anyone I would refer to as Ud. or Uds. using a reflexive verb, but I suppose I should still learn it.

Thanks!

[CrOtALiTo]

You can use the word Ustedes or usted and only you can use them, and for use the word Te en second person you can use with this examples:

Te recomiendo.
No me mal interpretes.
No te acerques.
No te aceleres.
No te animas.
No te veo.
No te quiero.
No lasvaste.
A donde lo lavaste.
Te tomaste el medicamento.
Te acostaste y te dormiste.
Te odio.
Te quiero.

How you can see in these examples the use of the word Te is a lot extended in the language Spanish, note not only are the unit word or phrases that exist n Spanish, it are a lot examples that you can do with the examples that I wrote you.

[Rusty]

The pronoun is se. Using the same verb you did, the commands are:
Lávese
Lávense

Have a look at this little table on the Internet that gives some sample verbs in the two persons you asked about, both in affirmative and negative forms.

[sosia]

agree with Rusty. The link is good.
¡callad todos! /¡Cállese usted!/¡Cállense ustedes!"
saludos
PD: Now the people say "por qué no te callas" .(little quarrel between King Juan Carlos I and Hugo Chavez)