What are some rhetorical devices used in Romeo and Juliet that relate to physical love?

To begin, we must first understand what is meant by "rhetorical device." A rhetorical device is language that is used to persuade, or to convey specific meaning. (See the link below for a list of rhetorical devices.)

The physical love between Romeo & Juliet is strongly alluded to throughout the play, but is particularly potent in the balcony scene. Consider Juliet's words in her famous "Wherefore art thou Romeo" speech:

What's Montague? it is nor hand, nor foot,
Nor arm, nor face, nor any other part 
Belonging to a man. (II.ii.42-44)

In this snippet, "nor any other part belonging to a man" refers rather overtly to genitalia. And in the conclusion of that speech, she goes on to say:

Romeo, doff thy name,

And for that name, which is no part of thee,

Take all myself. (II.ii.47-49)

In this section of the speech, she is offering up her virginity to him. Consider also Romeo's speech from the beginning of the scene:

Arise, fair sun, and kill the envious moon, 
Who is already sick and pale with grief, 

That thou, her maid, art far more fair than she.

Be not her maid, since she is envious;

Her vestal livery is but sick and green

And none but fools do wear it; cast it off. (II.ii.4-9)

In this speech "her maid" indicates Diana, who is the goddess of the moon and the patroness of virgins. A "livery" is a piece of clothing worn by servants of a lord or patron, and "vestal" indicates chastity. In this section of the speech, Romeo is asking Juliet to shirk her role as a virgin maid of Diana.

The language becomes more overt in Act 3. Consider Juliet's speech:

Lovers can see to do their amorous rites 

By their own beauties; or, if love be blind,

It best agrees with night. Come, civil night,

Thou sober-suited matron, all in black

And learn me how to lose a winning match,

Play'd for a pair of stainless maidenhoods. (III.ii.8-13)

In this speech, Juliet is essentially saying that lovers can make love by the light of their own beauties. Or, if they're not beautiful, then they can copulate in the dark. But she wants night to come so that she, and her new husband, can both loose their virginities together.

The play, being about teenagers in love, is full of examples of speeches about physical love. It is full of lust and the speeches are beautiful.