Temporary tank suggestions (sorry for all the topics)

I need to ge rid of my gravel and do a whole water change. I knew nothing about newts when I got them (bad choice) but now I know quite a bit and that my current set-up is not working with the gravel. I picked up a rock to get a worm that dug under there and all this (for lack of a better word) crud got kicked up into the water out of the gravel. Do you have any temporary suggestions for my two CFBN or do you think I should just put them in a big Tupperware and work quickly with my cleaning? Also, does shedding skin affect a newts appetite? One of them was shedding and hasn't eaten for about a week and a half. Any ideas?

Yes, you could move them to a tupperware tub, or even a small container with wet paper towels for a couple of days. As an alternative, I would suggest a more gradual approach to cleaning. Get a gravel-vacuuming siphon. Use it to remove some of the crud from the gravel. Replace water removed. Do this daily for several days, if necessary. Every day or two, remove some of the gravel. Clean up any debris that gets stirred up in the process. Eventually you will get rid of most of the gravel and it's associated crud. And you newts never have to be put in totally "new" water.

Which cleaning alternative you choose depends on how bad the current water is. If you think it's really toxic, then taking them entirely out and starting over may be the way to go. Do you have any test kits that would help you tell how bad it is, or isn't? Have you been doing regular partial water changes up to this point?

Yes, I have been doing partial changes, but my father put about 3 inches of gravel into the bottom and I am afraid tthe water may be very bad since I discovered the crud. Thanks for your help!