I'm only 125 miles into my immersive waxing. But so far it has been entirely positive. The cleanliness, which is my main reason for doing this, is fantastic. Also I don't have to faff about dripping oil onto the chain, wiping it off, disposing of oily rags etc. etc. And today I did my first ride wearing normal trousers, without worrying about getting inedlible oil marks on them. Fantastic.
Most of the riding has been dry tarmac, but very occasionally through a few puddles (some of them muddy), and some sandy tracks. Sand didn't seem to adhere. Very little rain from above though.
Many thanks to the advice from Sea of Vapours.