they do clean off this is what i use.
adamspolishes.com
can try regular all purpose cleaner on rag and some rubbing, like 409, simple green ect also.

Trim Cleaner
Prep your trim with Trim Cleaner to ensure a seamless bond with Ceramic Trim Coating and/or Black Trim Restorer. Removes oils and oxidation and makes your trim ready to apply protectant.
