The 37 force is a good effect to use on a single person, but your opener should engage the entire audience.
Just read something by Bob Cassidy that suggested a good opener, he asks the audience to think of an object, he names an object, and has anyone who thought of it stand up. The entire audience participates, and therefore gives him their full attention. Once many of them stand, his credibility is established, and one on one tricks can go forward.

Then again, even the 37 force can be used in this way; just do it on the entire audience at once.

There are a lot of Great ways to open an act, you want something that is sure fire, snappy and proves your credentials from the off.

If it is your first act here is a lovely piece that is simple and is nothing more than anyone else has offered here.

Position 3 chairs on stage, throw a paper ball into the audience, ask the person who catches it to throw it again and then repeat (that is three random volunteers)

state that a lot of your job is to influence peoples behavior and you would like to demonstrate,

perform a simple chair test (there are loads on offer P.M me if you need guidance on what literature to read).

after correctly predicting the outcome of a chair routine remove a buisness card from your pocket and a pencil, place them behind your back (this is a good excuse if the writing looks a bit shabby from the swami).

Pretend to write a 3 digit number, look at the card go urghh (as if to state the writing is a little shabby with out saying it) throw the pencil into the audience (this will over exaggerate the fact there is no pencil)

stand the participants ask each one to look at you and imagine in their minds a single digit make it bold and bright and when they are happy they have one state it out loud (swami the three individual digits on).

hand the middle subject the card, tell them to hold it face down and then ask them to repeat their numbers again and state 'ok we shall place these three peoples random numbers to together to make a three digit number, you are all happy that was free choice?'

hold the mic up to the middle subject, can you please state what the digits are on the card?

(let the impact hit the audience as you ask for a round of applause for the three subjects)

VERY VERY simple sure fire and screams RANDOM (paper ball, free choice of chair and then number!)

(if you was a little more fluent with a swami i would suggest writing their initials and asking just after you have handed them the card if you have ever met to which they will respond no of course not)

Hope this helps