We often use pedal / collective to slow the blades, however generally only in a wind as the damn things won't stop themselves (no rotor brakes). If you do it gently you will actually reduce the beating that they get by leaving everything centered... 206 and 204's, and only start playing with when less than about 30% or so, no slippery surfaces, so not much chance of going round.
A worse habit I have seen, is standing outside the machine, leaning in and shutting it off.
with that quick whack of the throttle, if you do it the wrong way you are in for some fun.... Have even seen guys lean over the left seat, on right hand drive, and whack it off. Surely an opportunity to get it wrong. Before you go off about getting out of a helicopter with blades turning, let's forget that as it is well covered, and outside Europe seems to be a well accepted practise, main reason it goes wrong is when they leave it at flight idle!
