Thanks so much for the hints!
Over here seam rippers do have Quick Unpick on the packet, it's what they've always been called. Not sure if I'm allowed to put links for advertising, so if you google "quick unpick" and "New Zealand" you'll find one.
And funnily enough, hubby does have one of those moustache trimmers! What a brilliant idea, I'm going to try that tonight! I normally do the every third or fourth stitch thing too, but because this is black and there are so many seams, I've given up, just can't get a good rhythm going.
I managed to get quite a bit done last night while yapping on the phone to a mate, so feeling a bit more positive this morning. Will report back when I've tried the trimmer.
:-)