I have a variety of wipes- bought some, had some sent free with diaper orders, and the bulk are cheapy terry wash cloths.
We use plain water.
We keep a peri bottle of water at the changing area and a little spray bottle of water in the diaper bag, but I like to go to the sink for a warm saturated wipe when I can. I like the idea of a thermos (with a pump) of warm water but haven't purchased one yet. I was carrying pre-wet wipes in my bag but found that I didn't always need them all and worried about them getting forgotten and sitting wet.
I've put a bit of baby wash and olive oil in the bottles before...but I wash my wipes with my diapers and now wonder if they should have been washed separately...
I'm new to CDing in general since my baby isn't even 4 months yet, but a tip I just figured out

...when using a cream or lotion you aren't sure about as far as CD safe, put the wipes in with baby's laundry instead of the diapers. I had been using a liner to keep cream off the dipes and then wiping her bum with a wipe and putting it in with her dirty diapers...ugh. Lack of sleep does crazy things with my ability to problem solve, lol.
Once she is eating solids and her poops change I may reassess the plain water.