I've never been able to cut with those disks long enough to get through an entire chain without shattering the disk. It's not a big deal to change them (and I always use a face shield when cutting) but it's just not worth the bother getting the tool out and swapping discs >1 times. Is there a beefier cutting disk for the dremel than the little 'splody ones that come in the cylindrical package of 50?

A big +1 to the CT-3. It's a great tool.

Even though it isn't really specified for use on single-speed chain it does fine as long as it fits. Some of the beefier heavy-duty BMX chains won't quite fit in it but your typical run of the mill 1/8" bicycle chain will work on the CT-3 just fine -as will the original chains that come on old 3-speeds and single-speeds from the vintage era. Just be careful to keep it lined up well and tips are not a problem. I've yet to break a tip or bend the lips on mine. If you are lazy or in too much of a hurry to get the chain pin lined up correctly the tool is quite capable of exerting plenty enough force on itself to ensure self-destruction.

When in a hurry to extract junk chain from a bike an inexpensive bolt-cutter is the best quick alternative. If time is not of the essence and good lighting and easy access is possible then the wear on the tool when properly used and positioned is very minimal -even when the chain is not going to be reused.