How can I quickly and safely make defunct electronics safe and free of charged capacitors?
I feel that giving all of the items a salt water bath is probably the best option for your circumstances.

However. Do not dispose of the water carelessly afterwards. There may be traces of lead and other nasties in it. Find some sort of hazardous waste disposal company and get them to get rid of it (it may cost you a few $$ but it will be quick and fairly safe if you are careful, rubber boots might be a good idea). Also, I have no idea how well sealed up everything is inside them but some of the capacitors might not be shorted by the water properly, if you don't go digging through things that look like they may act as a sealant and you make sure you get all of the air pockets out when you give them a bath I think you should be OK however.