This technique used to be recommended with the old Tamiya armor kits. My instructions for the old Tamiya PzKpfw III Ausf. M/N describe using this technique for recreating the German armor camouflage. Also my first "how to" book put out by Testors talks about the sponge painting method. It says to use the small cell, man-made sponges to give the best look.
I've had this book for ages, at least since the early 1980s. The technique is probably still utilized to this day. I think I tried it first on an old Revell 1/72 scale Stuka that I tried to do a winter camouflage pattern with. I think I cut a small portion off of mom's kitchen sink sponge. It turned out ok to me back then.