I've done it once; its the first entry in my dream journal here. That was with WBTB (wake early & stay up for a while first), which is essential, at least to start with.

Vex Kitten's amazing dream journal here has a WILD a few pages back (you could search user=Vex Kitten, section=Dream Journal, keyword=WILD, and of course there's probably more if you search on all users).

It does exist. It is pretty damn cool. But it's really challenging. TANSTAAFL .

Unfortunately I don't have a link to an impeccable peer reviewed article substantiating WILD :-). Not as good as what LaBerge did with MILD and DreamLights anyway.