Magic the gathering Combo question?

Lets say my opponent has 6 no special abilities, and I have a phyrexian walker (0/3) equipped with Nemisis mask (all creatures able to block equipped creature do so) and Dead Iron Sledge (Whenever equipped creature blocks or becomes blocked by a creature, destroy that creature and equipped creature.) and a welding jar. Could I attack for 0 with the Walker, then all 6 creatures would zero, all get destroyed and I could save the walker with the welding jar?