Lecithin powder worked like a charm for me. It made it thick and voluminous. Only problem was my wife had problems swallowing because it would get stuck in the back of her throat (and it really was just way too much). So, she gave me a choice. She'd either stop swallowing my cum if I kept taking the Lecithin, or she'd swallow if I went back to normal.
I happily stopped.
I was using the Now brand, and mixed in 2 tablespoons with a glass of orange juice in the morning.