I've never used Scotchlocks, but I've seen them in packets in various places selling 12v stuff, and they look like a hazard waiting to happen...
I'd rather use Wire Nuts (or Marettes as the Canadians call 'em) over them and even the ol' chocky blocks, they're secure, they're reusable, and they're very reliable:
http://shop.ebay.co.uk/?_from=R40&_trksid=p3984.m570.l1313&_nkw=wire+nuts&_sacat=See-All-Categories
(they're the coloured thingies, Blue, Yellow, Red, Orange and Grey, all different sizes)
They work on solid wire, stranded wire, bare copper, tinned with solder, etc., and they're safe enough that american and canadian homes are wired up with them, can't say fairer than that...