I generally get out a computer program and use that to roll dozens of times in the blink of an eye. usually I use the
nbos Inspiration Pad Pro, because that's my gaming random generator of choice*, but that requires a little technical work to make it do dice from its original form. It does let me roll an arbitrary number of dice though.
If I want to roll a really high number of dice (over 100), I'll write a quick program that gives me the number I need.
I've been meaning to publish an html doc that will do that for people one of these days. This pushes me to get down to doing it.