Hi and thanks.
Short answer - dry.
Have a look at this little video. Rupes is one of the absolute top notch manufacturers in the detailing game and what they don't know about polishing isn't worth knowing.
https://www.youtube.com/watch?v=txh-t6IrcSQ.
And something a bit more general but very well worth watching
https://www.detailingworld.co.uk/thr...thread.281047/
And if you get the bug come over to
https://www.detailingworld.co.uk/ and see what's going on there (yes, my username is the same and there's a fair few of us on here that are on DW also.).
Cheers.