Thanks for posting
@Jacques!
Couple of comments. Swix Glide Wax Cleaner, IMO is just magic. My son gave me some. He's an alpine coach, and a couple of years ago one the nordic techs turned the alpine techs at his program onto it.
I'd reach for denatured alcohol, too, and try to get in on and off the base as quickly as I could. This past summer I had to remove quit a bit of sap from one of our cars. Obviously the finish on a car is harder and different than a ski base. Still, I wanted to remove it with the least aggressive stuff that I could use. One of my neighbors is an older, old school car collector.
His suggestion was Mineral Oil. Worked like a charm once it "got to" the sap....into it. I figure that if you can put it in your body, can hurt clearcoat, and might not dry out a ski base.
Haven't had this happen to a ski in a few years, but last time I remember thinking "now that's a pain in the ass...."
Thanks.