There isnt any reason you cant take water from another tank and dump it into the tank w/ issues - but I agree w/ dwilder, its pretty useless. You really are just taking dirtied up water and putting it into a tank with dirtier water... and that dirtied up water is just going to get as dirty as the water already in the tank, only faster than clean water would... remember, its your bio-media thats going to help with ammonia - not your water... water doesnt clean water...
Id suggest the media trick. If you have a power head, get a sponge filter for it and put it in one of your well established tanks. It will build up good bacteria - then take the sponge and squeeze it into your tank w/ ammonia issues, then put the sponge back in the established tank. Repeat until tank w/ issues can sustain itself. Meanwhile, continue the water changes to keep the ammonia as low as possible.
Em