why survive a day or two ??? a lage goldfish will last a day or two so would a large bag of neon tetras..
there is a fish that would be the perfect tankmate for your pulchra , it even shares the same temp requirments , same food preferance , and will last even longer than two days .
the perfect fish is another channa pulchra
i would strongly suggest you leave out the crayfish ot lobster , there is a very real chance of it killing the pulchra overnight while it is asleep. if really small then the pulchra would more than likely try and eat the lobster.
i know this will not be what you wish to here , but i would be doing you a dis service if i suggested another type of fish. what you must understand is that if you want to mix your channa with other fish ,then you gamble with the life of the channa and the other fish, the odds would depend on which fish you chose , but it is not fair anyone suggesting a fish to you when there are no promises it will work