I have not looked at Caster oil TBH. I am not aware of it having any Urease Inhibiting effects. I am only aware of a relatively small list of herbs which have been tested as having UI effects. Brown Seaweed is meant to have UI effects which was briefly mentioned in the paper linked below. There are almost certainly many other herbs with UI activity but most have not yet been identified.
Urease Inhibitory Activities of some Commonly Consumed Herbal Medicines
Ginkgo and Sumach followed by Chamomile are the three best UI herbs, Ginkgo being the best and strongest by far. Unfortunately it has some risks, liver cancer being one which is why I no longer use it which is a pity because the positive effects suit me by a considerable degree. Be aware that the German Chamomile mentioned in that paper is not identified correctly. Matricaria inodora is not German Chamomile it is False Chamomile which calls into question what they actually tested. Sumach looks promising, it has fairly reasonable UI activity and is also strongly anti-inflammatory.
Treating ammonia after it has been produced puts a big burden on the bodies detox and eliminatory channels. Stopping it being produced is a better method IMO. Destroying the pathogens causing it is the best method of all. Currently science/medicine does not recognise any other stomach pathogen other than h pylori which itself took some accepting. It makes no sense whatsoever that h pylori could be the only stomach pathogen because there are too many ulcer and stomach cancer cases with unidentified causes. I think that those cases are caused by other stomach pathogens IMO. Such pathogens affect everyone on this forum IMO.