Before WAM material got properly established as a fetish in its own right, top shelf mens magazines did do the odd messy photo shoot. There were usually a bit crap, but the odd one wasn't bad.
One pretty decent one I remember from sometime in the late 80s was a series of stills from what must have been a very early WAM video shoot and I think it was called "Battling bimbos creamy catfight" It was a bride and bridesmaid, both very attractive and dressed in gorgeous dresses, the bridesmaid's one was blue, getting involved in a messy pie battle, and ripping each others dresses off.
I don't know what magazine that was in, but I had that magazine, I think, and it spurred me to buy the video (on VHS, so no way of accessing it now, as my player eats all the tapes.) The company that made the vid those were stills from, I believe, was called California Wildcats. They also had a nice mud one called "Dirty Farming.| http://www.californiawildcats.com/bridal.htm
My brothers stash of porn mags had a copy of Fiesta in that had a great custardy session in and another one on the cover gad 'rice pud wrestling' - but these were later - I'd say 95 onwards. Dkdo the back of his Loaded magazine had a random advert of a woman with custard dumped all over her. Oh & I've mentioned before I was the kid who wrote into FHM problem page which they published under the title "Custard Gives Me the Horn" along with a really horny pic. The Internet seemed unattainable at the time do these things really mattered!!