One of the definition I know of any reflexive is to do to oneself.
I am not sure if this is only limited to passive voice:
Se frotan las manos por Jóse. (The hands are rubbed by George)
Ok, here is a sentence from a published textbook I am reading:
Frota su cuerpo con loción.(He rubbed his body with lotion)
But I think reflexive verbs also work here:
él se frota el cuerpo con loción. [To avoid the confusion with passive voice (the body is rubbed with lotion), I added "él".]
I am not even sure whether the confusion will happen.
Or to say he rub himself with lotion:
Él se frota con loción.
But my teacher said I use reflexive only when something like "en él" is used.
Él se frota en él con loción.
please, please, make as many correction of whatever I said as possible. Anything will help.