Hi,resting on a plate will have a similar effect for tenderizing the flesh,but will make no change to the flavor,you need the guts in for that.
In my opinion the best thing to do is get an old fridge from somewhere like pre loved,you can get them for as little as £5 on there.Take out all the shelves etc and fix a couple of lengths of wooden down inside at the top to hang the birds off.You can hang up to 3 birds (large cockerels) at a time in there.
I like to hang mine for 4 to 6 days with the guts in,I have hung them up to nine days without any problems.
Graham.