To put it briefly, leather cleaner won't cut the mustard with urine.
Urine comes out as an acid and, as it dries, changes it's pH to an alkaline salt.
In cases of high humidity such as when it rains, the alkaline salts absorb moisture & off-gas the ammonia odor, so very common with urine.
The type of leather must be considered.
If it's an unfinished leather, the urine has possible penetrated the leather.
If it's a finished leather, it has probably gone across/over/down the sides until it has come in contact with a fabric, then migrated into the Dacron or foam, depending on the severity.
I have found that Concrobium to be one of the best products to deal with urine.
Concrobium comes in two different types.
One is a mold eliminator, the other a mold stain remover.
Ozone will do nothing for the urine odor so far as I have found.
The cushion material is where you will find the biggest problem, this is the source that must be eliminated.
Don't over promise on what can be done in these situations, especially when others may have tried
"great info; from the internet or good friends".
I don't regret my past, I just regret the times I've wasted with the wrong people.
Take me as I am, or watch me as I go.
I'll retire when I can no longer do what I love, or I no longer love what I can do.
Stop moving, start dying........