Combining PSU outlets

Snags

In this video Mr Cioks talks at one point about combining more than two outlets from a power supply, but carefully doesn't mention exactly how one would do that reliably/safely. (About 10:35)

Presumably if you needed to use 3x outlets to get the power required you'd use two of the combiner cables, and plug the second one into the third outlet and the 'out' of the initial doubler?

I have emailed Cioks with a query, and asking about exactly which cables they would use and in what combination, but either they haven't got around to it (fair enough, not a priority question) or they think it's too dumb to warrant an answer (probably also fair enough, but I like to be safe with these things). Figured there's more than enough assembled knowledge of electrickery on here to get a sane answer