Hi,
Many years ago I used fox urine and I noticed mixed results.
Then I went with raccoon cover and it seemed just ok.
I am now more partial to earth cover scent and or rabbit urine.
There was a time when I went fox urine and doe pee (Tinks) in two different 35 mm canisters.
I would set the doe pee canister about 15-18 yards from stand/blind and the fox about 10-12 feet away to the right of the doe pee canister (since I shoot left-handed). I would use a cutoff piece of an arrow which I taped the canisters on and marked my arrows with night-bright glow tape; so they where easy retrieval for me at night, and the way that I would mark my pee containers on the arrows is with 3 marks of glow/night tape for the doe pee and four marks of the fox pee; which meant for me is 3 for pee and 4 for fox and when I would stop hunting for that late afternoon/evening I would take my pee sticks and put those in my quiver.
I have heard about using skunk cover but it seems too alarming to me, but I have also heard/read another way of using skunk cover was after you leave your vehicle to take a cotton swab and dip it into the skunk cover and drop it near your vehicle to cover up any gas/oil smells.
I still like the baking soda for washing your clothes theory.
I hope this works for you.