Jetwash or not?

I now have my body shell ready to begin a rebuild. It has baked on mud where we would have damp compost in all the nooks and crannies being from a warmer climate. I want to begin to rust proof asap before any moisture gets into the shell but I am worried that jet washing will simply force water into places I don’t want it. So should I chip and brush the mud off or jetwash and leave in a heated garage for a time to ensure it is dry.?
I don’t actually have a heated garage though!

I would chip and brush , that way your know every inch of the body .
I would do one section at a time , like under a front wing , clean it off , then rust proof it , then move on to another section !