If a colander doesn't work for you, maybe putting the bones into a small bag might work.
I do this sometimes when cooking on the stovetop. I have a metal colander I put the bones/carcass into, and just lift it out when cool enough to grab and let it drain and dump the bones/gristle after.
I usually just throw everything into my slow cooker and then strain through the metal colander the next morning. It's a bit more fussy that way, but the colander won't fit the slow cooker, and I prefer using the slow cooker most of the time for bone broths (as I can leave it running for 24 hours and use very little energy and not worry about running a quick errand out of the house).
And for leftovers, I use broth and leftover chicken to make chicken and dumplings most of the time. I use tube biscuits as a quick shortcut for the dumplings. Take 2-3 biscuits and flatten out until about a quarter inch thick on floured surface, then lightly dust tops with flour. Use a pizza cutter to make small strips. Bring ~4-6 cups of broth (can stretch a good thick broth with water) to a low boil, add in biscuit strips and gently stir. They'll puff up and float to the top when good. Add in a bag of frozen peas (or peas and carrots) and leftover chicken (or even canned chicken) and bring back to a simmer, and then add in a teaspoon of flour at a time, stirring, until broth thickens. Takes about 20 minutes start to finish and so far I've had nothing but rave reviews considering how fast it is to make.
