I did actually see Reindeer leg in the freezer section of Lidl yesterday, I was tempted, but figured the kids would NEVER forgive me!!!
As for DMX, you might find it's not cost effective as you'd need a demux controller for every string that you want to switch (at around ÂŁ50 ea). Instead, you can USB dongles that will trigger relays (seen them, don't know much about them) and if you want to use PC control then you could use MIDI trigger instead, and fire them according to a time-track on a piece of music, for example. All the software is easily available as free downloads.
OR, just thinking about it, try fleebaying for an ex-rental theatre style dmx demux unit with 6 x DIN analogue outs on it (so n number of channels grouped in sixes - typically 36 outs per unit). That would get you some 5v analogue outputs (NON latching - constant refresh) that you could then use to build a relay centre. You could also probably find some ex disco tat DMX controller to program for the job, too. Depends on how much you want to spend.