I just went through this so I have some opinions! I purchased these expensive-for-me Acne booties in a completely impractical color. The first day, I didn't have time to treat the boots and I got scuff marks on the inside heel areas (on both feet!). I tried the Magic Erase. No avail, although this product has been great for the white wall portion of slip on sneakers. Then I tried a Q-tip with nail polish remover. BIG FAIL. The nail polish remover actually removed some of the suede. But did nothing for the spots. Fortunately they're not huge scuffs and again they're on the inside so not too visible.
Since I was on short vacation I didn't wear the boots again after that first destructive day (a long car trip, although I did none of the driving). When I got home I finally applied a Woly Wet Blocker which is similar to what KiwiGal/Sally recommended to me on another thread. I was nervous that it would darken the suede but it has not left any residual traces. Plus, I have worn the boots again and this time, no scuff marks (I'm really hard on shoes). I've applied the spray twice more, and even dropped something dirty on the shoes with no incidence.
Actually the product Sally recommended was this Woly 3x3 Shoe/Boot Protector, which was out of stock but now back in stock but selling fast. There were 12 in stock when I last looked, now there are 6 (I'm buying it after I submit this reply!). I also purchased this Woly suede brush. These are pricey shoe care products but I think worth it.