Sponge chipping is to create random small chips quickly, so 3 of the 6 supplied sponges are way too big & will cause awful large chips that'll look unrealistic. So you're getting 3 small bits of sponge for £15 or so ...
Plus attaching them to that handle will restrict how you can use it. Spend your money on a few good 00 & 000 brushes & a pack of sponge scouring pads - the rest is just snakeoil.