I’m thinking about screwing a small piece of 2 x 4 to a bench outside and make a jig to slide the container thru and cut if off with a reciprocating saw, now. I have the bench/table built and all it would take is a 2-4" piece of 2 x 4 and a few screws to do it. Maybe two-pieces.
If you go Sawzall, go with metal blades and measure the diameter of the pot. Go with a blade at LEAST 2" longer than the diameter; I play that game all the time at work and you don’t want bent blades from getting stuck inside the plastic from the return cut.
I second utility blades, a 50 pack of Milwaukees is like 15 bucks shipped on ebay last I checked, that will last a long long time.
I’d bet the paper cutter would go through all of that 100 times. You’d need to remove the guard rail, and it would probably be “ruined” in the sense that it wouldn’t be good for cutting paper, but I bet it could be returned to service for chopping pots. May take some touch up of the blade.
If you have more time than money, you might try Goodwill or the like for a dirt cheap used one.