dilutants

Hallo all,

I was wondering if anyone here has experience in the field of dilutants. More specifically towards what diltutants to be used and why.
Its a general well known fact that a lot of institutes use saline water to make dilutions when working with fungi or bacteria , but is there are their well documented cases on why saline is good? Or what about alternatives? Like distilled water or peptone water??

Any info on this?