Bicycle pump is wot I used.
A plastic pipette with the bulb cut in half longwise to make a wee totty spoon and puffed wiv a short blast from the pump worked better than the powder lying on the bottom of the can.
Too big a blast just blows out the candle.
Briar Rose crashing your thread somewhat but to save repetition
I'm retiring tomorrow too and have read all the above good wishes from everyone and applying them to me too
Thanks to everybody on here.
Exploding custard (icing sugar gave me better results) can is pretty much trial and errorwith candle flame position and height, input method and getting a good puff cloud.
Had a few good bangs and the lid contacting the ceiling more than once.
The icing sugar also gave a lovely colour coming...