The Cluffy Wedge is an orthotic modification or 'add on' that sits under the hallux to hold it in a slightly dorsiflexed position. Something similar has been in use for a long time, but was first described under this name by Dr James Clough in a JAPMA paper. The description of it was as modality to treat functional hallux limitus.
One anomaly that I use the Cluffy Wedge or a similar sort of modification is in those with a delayed onset to the windlass mechanism (more). When standing you can dorsiflex the hallux and in some there is a delay before you can feel the resistance provided by the windlass mechanism. What this means is that during gait, the heel will need to come off the ground a reasonable amount to provide sufficient hallux dorsiflexion before the windlass starts working. As the heel is coming off the ground, the windlass is not working in these people, so there is nothing supporting the midfoot. The way to treat this is to ‘preload the hallux’, which means getting load onto the hallux earlier by dorsiflexing it, so the windlass starts working sooner. A heel raise can do the same thin, and sometime you need to do both.
The concept of preloading the hallux is not new, but it has certainly been popularised with the use of the Cluffy Wedge (more). See the PodiaPaedia entry on the Cluffy Wedge for even more.