I dont use anything on the wash stuff as it has shampoo on on the cloths already so just put them through on 40 degree wash...
Dont put washing powder on as it dosnt always disolve fully and then you get bits that will scratch your car..
Dont use conditioner as it stops the water collecting in the cloth, as it leaves a "waxy" type residue, woman at House of Fraser told me that one when I was buying my bath towels!
Dont put anything with polish or wax on in the machine or your machine will stink for ages as will all your clothes!! Found this out last weekend!! I now put the polish / wax cloths in a sealable bag and then attach them to the bottle / tub with an elastic band... Or write the name of the wax / polish on the outside of the bag...
Just bought some AutoGlym HD wax at the AutoTuner show at Brands Hatch and used it for the 1st time on Friday, great stuff, comes with 2 application pads that are already damp in a sealed bag, and a microfibre polishing cloth, goes on real nice after polishing... One coat so far, wont be long till I got about 10 coats on am sure... Washed it twice, polished with autoglym polish, waxed with HD then finished with Megs quick detailer, looks v nice