Whilst some climbing walls seem to have a bit of a bee in their bonnet about GriGri use and try to discourage it (and who can blame them with all the accidents improper use has caused), at The Castle we are happy for any kind of belay device to be used so long as it's used properly (ie according to the manufacturers instructions).

Petzl, the manufacturers of the GriGri have helpfully brought out a video showing proper and improper use of their belay device: GRIGRI - Belaying the leader by Petzl-crew

So all you new-school GriGri users, please watch and learn! And just as importantly, all you old-school-thumb-over-the-top-squeezing-the-locking-mechanism GriGri users beware: There are several different acceptable methods of using a GriGri to pay out slack quickly for a lead climber and putting your thumb over the top and squeezing the device is NOT one of them!