Turns out that the office never had a shredder due to noise concerns
and we seldom have work documents that demand such treatment.
Noise is an excuse, not the actual reason.
Shredders aren't all that noisy, and could easily be operated after hours or in a utility closet where nobody would be disturbed.
Most likely, they simply didn't want to spend the money. Perhaps they were just being frugal, or perhaps they were misguided.
But one day the unexpected happened, and we had to literally burn the
stuff up in the toilet (with care, of course).
Burning would work.
Of course, if you set off the smoke alarm it will be far more noisy than a shredder. And if you burn the building down you would have to work outside and listen to traffic going by - that could be noisy too.
How do others deal with such a situation?
I worked at an 8-person startup. When we collected paper that needed to be shredded, the CEO took it home and shredded it there. You could take it anywhere a shredder is available (an office-services shop, home, whatever) and get it shredded pretty easily.