hm interesting, mind you Dave you forget that UK kids are not going to be know where near as clever and less patient and be outside sticking their faces over reversed caps waiting for them to blow in their faces before your blogs finished(yes we brits are pretty dumb and stupid these days, most people i know beling in a insanity home as they can't cope with the realities of life like cooking a meal even!), I'd suggest safety warnings first to be honest.
I remember as a kid when I accidently reversed a 3300 uF 25 V cap at 18 V, my that shot acid everywhere, I was lucky it didn't hit me in the eye, I had repaired a power supply and yes put it back backwards. I learnt a sharp lesson that touched my limited finaces at the time rather deeply.....