I took a cutting from one of these, given to me by my Bangladeshi friends last year
[attachment=3]
This is it today, looking much better than the parent plant which grew much too tall for my kitchen windowsill.
[attachment=4]
I don't know if it's possible to take cuttings from all varieties, but it's worth a try
edit - sorry, messed up the photos.
I took the cutting from one of the tall ones on the windowsill.