I scratch-mix my C-41 chemistry using PhotoFlo-200 + formalin for stabilizer, with distilled water for mixing. I use 1-2 min. in the stabilizer and I too usually find drying marks. I have long run the sponges along the wet film before drying and this eliminates any of the remaining drying marks. I wet the sponge in wash water or stabilizer and squeeze them out thoroughly before wiping. The result is always clean film after drying. The only effect to which I can attribute drying marks is low humidity that is the norm in New Mexico. Wet film dries very quickly here usually in about 15 minutes.