I would guess running the outflow valve manually closed would give a more severe rate of descent ( from 37,000 down to 8000) than 1000fpm,anyhow you are not going to hang around 7 0r 8 mins watching the cabin altimeter. My guess is that the response to motoring the valve closed would be quite rapid, not nice for the ears, but then again neither is a 5-6000fpm unpressurised emergency descent or indeed a rapid climb from 8000 up to 37000 ? following the problem.
I know the outflow valve is a fairly large flap to have hanging open but I was always led to believe that the volume of air coming into the fuselage combined with the area concerned resulted in any decompression being less than "explosive" unless you lose your roof Aloha style, quite unlike a tiddler like a Lear.
Anyhow, finally I wasn't there, but it will be interesting to hear if the descent was warranted or whether control was indeed possible.
At the end of the day no harm done by getting it down sharpish, unless you forget you are over the Alps.