I know this isn't a complicated question but I just want to make sure I'm getting the right product. I've been using a SS brush during the first 2 weeks since my pool was plastered. My pool guy said I should switch over to a nylon brush because it might be too hard on the plaster. I've been reading and some say you need SS to help the plaster cure. Who is correct? Also, would a combo brush like the one linked below be the best of both worlds?