Fermented feed is very much like sourdough bread- the exact same process is involved. I'm not a fan of the slightly sour smell of either FF or sourdough, but neither should be horrible and overpowering.
Add as much water as the feed can absorb- about a 1:1 ratio (I use about 1.1 parts water). I'd recommend starting over with a clean/sterilized container as you don't want to transfer the current bacterial culture to the new batch. Use a smaller amount of feed until you are comfortable with the results- 1 pint/quart/gallon depending on the size of your flock.
The tiktok.com link in
@lazy gardener's signature is the best reference.