You can do it in a rubbermaid container---but due to need to see fish, I'd suggest a tank is better. A thin-glass tank would be ok for this application, since no rock or sand.
Your only other option, and you might lose all your fish---is feed a mix of regular food and pureed fresh garlic, and hope they throw it off. Garlic does seem to help them resist the parasite, maybe operating a little like Advantage. You should not, then, add any new fish until several months have passed. Inverts, again, ok; and corals I am convinced eat the ich at some stage of its life.
Understand, if you take this option you may end up with a tank with no fish at all, or a tank with one fish left into which you cannot safely put even a quarantined new fish within the next couple of months.
If you get out of this ok, do quarantine everything in future: big tank, big problem when this happens.