This page on my website will probably be of interest.

Vinyl Restoration

Don't use tap-water, with or without anything like washing-up liquid, unless you know that you live in a soft water area. Over much of the southern UK tap water is sourced from chalk downland, and is very hard. Using such tap water to clean vinyls is likely to leave limescale on them.

Distilled water, however, is fine. My vinyl cleaning machine recommends a 1:4 solution of Isopropyl Alcohol, which means one part IPA to 4 parts distilled water, or so I believe - schoolboy chemistry is a very distant memory.