From what I know about it, beldi soap is a KOH soap made from olive oil, olive paste, and sometimes mustard oil or other oils. It's normally left as a paste, not diluted to a flowable liquid, but I don't see any reason why you can't dilute it further. The only thing is being all or mostly olive oil, it may not want to stay a flowable liquid unless it's diluted a lot. But try it and see -- maybe do a test on a small portion.
Yes it can be diluted. I dilute mine in 1 paste : 1.5 rose water to easily use it in the shower. it may clot after 3 months and you can just add water and shake it. I love using it.