How do I clean a few spots off my polyester couch.....?

I'm renting a heavy duty steam cleaner to clean the whole thing. But for now what household product could I use to clean some dried chunk areas (spot of throw up and something yellow). I have absolutely ZERO upholstery or fabric cleaners in the house . What do you recommend, and how do I prevent those wet rings that never go away when you spot clean? Thanks in Advance !!