I've heard it before; it was meant to convey secrecy and did not actually refer to any cultural practice.
The British empire with its colonies spread over the South Asian/South East Asian subcontinent encouraged the import of quite a few Persian/Indian loan words into Brit English and these were once pretty widespread in popular usage. 'Have a dekko', 'good ol' Blighty', bungalow, dhow, dinghy, verandah, mufti, dacoit, chitty, juggernaut, pukka, pundit along with the more familiar curry, vindaloo, balti, cashmere, pyjama, chutney, typhoon, thug, karma :) .
We seem to have purged some of the more exotic ones out of our regular vocabulary. Not many people would recognize some old loan-words in their original context any more, especially this one. Worse yet, it would be very easy to misinterpret the usage and the sentence would end up giving out unintentional negative vibes. It really wouldn't be considered too appropriate in a professional setting imho but it depends on where you're planning to use the term.